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Central Nervous System (CNS) fatigue is a phenomenon mentioned in training room conversations, at lectures, and in coaches’ forums. The term itself seems to be well-accepted. But as one delves into investigations on its etiology beyond a Google search into the realms of peer-reviewed exercise science, clear applied scientific information becomes vague and scarce.

Introduction

Much of the work done on mechanisms behind CNS fatigue offers reasons why fatigue results from prolonged endurance exercise. There’s also research into output-related illnesses such as chronic fatigue syndrome. When we switch gears and examine CNS fatigue under a physical preparation lens, information to substantiate the biological theory that it results from high-intensity (speed and power) exercise becomes much more elusive.

As coaches, however, we likely agree that we cannot plan for successive high-intensity sessions without negative consequences. Or can we? Perhaps we do not know. Or perhaps it’s highly individual or subject to the logistical and traditional constraints of western sport models and common periodization schemes.

In the book, The Charlie Francis Training System, Francis discussed how optimal CNS functioning might look in a high-performance athlete. He suggested, “optimal transmission of nervous signals” and “motor pathways, characteristic of optimal technique and efficient routing of motor signals must be in place.” CNS fatigue is reached when the “by-products of high intensity exercise build up to a point where the CNS impulses (necessary to contract the muscle fibers) are handicapped.”

According to Francis, this is caused by:

• High-intensity work occurring too frequently in a training cycle
• Too much high-intensity volume in a single training session
• Introducing high-intensity training too rapidly into a training program when “residual fatigue still exists.”

Francis offered examples of high-intensity, CNS-taxing work:

• Sprints at maximum speed or 100% intensity from 30-120 meters
• Heavy weights allowing only a few repetitions (2-5)
• Explosive jumping and bounding (plyometrics)

Whenever athletes focus on maximum speed or explosiveness, they tax their CNS. “Low-intensity workouts (65-80% 1RM) leave the CNS relatively intact,” Francis explained. Recovery from CNS work requires at least 48 hours before a similar dose. During this period, the athlete should undergo recovery strategies to restore homeostasis.

“At the highest levels of sport there is a quantum increase in CNS output for every increment of improvement. A 95% effort might require 48 hours of recovery, whereas a PR (100% effort) might require 10 days of recovery,” Frances stated.

It appears there is a margin of recovery that should not be taken lightly when we differentiate between 95% and 100% of max speed or power. Perhaps, then, it’s important to highlight the importance of rest and recovery, proper spacing of training sessions, and load monitoring. Perhaps understanding the following two questions will allow us to improve our practice as coaches:

• How is CNS fatigue created?
• What are the possible mechanisms that underpin this phenomenon?

A deeper understanding of the operations of the CNS has grown over the years, linking biological rationale to phenomena we observe as coaches or sensations we might experience as athletes. However, much of the work on CNS fatigue and its role during exercise is done during prolonged exercise and in clinical exercise physiology and medicine. In the physical preparation of the speed-power athlete, perhaps we are following rules of a game we do not yet fully understand.

When training speed-power athletes, perhaps we’re following rules we don’t yet fully understand. Share on X

Most investigations suggesting the CNS plays a role in fatigue are restricted by the lack of “plausible biological mechanisms” and are “relegated to a role of a black box phenomena” which are hard to defend.³

Let’s Define Fatigue

Fatigue experienced during exercise is defined as the “inability to maintain a given exercise intensity.”² It includes an acute impairment of exercise performance that leads to an increase in perceived effort and an eventual inability to produce high quality and high magnitudes of muscular power.³ Fatigue can vary with the nature of the activity (intensity and duration), the athlete’s training status, and the present environmental conditions.²

The causes of acute fatigue are interrelated and complex. Fatigue can be elicited by depleted energy stores in muscle or by accumulating metabolites within the muscle cell. Fatigue can also result from a failure of neural transmission outside the muscle cell within the nervous system,⁶ which is the focus of this article.

Neural or nerve transmission is the process whereby signaling molecules (neurotransmitters) are released by a neuron (the presynaptic neuron), and bind to, and activate the receptors of, another neuron.⁶

It’s important to mention that fatigue also has roots in psychology. For example, the limits of physical stress may be consciously or subconsciously limited by the athlete’s pain and work tolerance.⁶ Motivation and perception ³ and their effects on performance have been documented for years.¹

It’s difficult to find a specific definition of CNS fatigue. Davis and Bailey explained it as the “failure to maintain the required or expected force or power output associated with specific alterations in CNS function that cannot reasonably be explained by dysfunction in the muscle itself.” Somehow the ability to maintain CNS drive to the working muscle(s) is compromised.

In other words, if it takes more stimulation (CNS input) to produce a desirable level of muscle contraction (output), then the CNS is likely fatigued. This indicates that the muscle itself is less responsive to the degree of input it’s receiving from the CNS.

Evidence for a specific role of CNS fatigue is limited due to human physiology’s constant flux. Share on X

Acute CNS fatigue, although accepted as real and valid, warrants a deeper understanding of the mechanisms involved. Evidence for a specific role of CNS fatigue, however, is limited by the lack of objective measures due to human physiology’s constant state of flux. Understanding the neurophysiological mechanisms behind CNS fatigue may lead to a better understanding of human adaptation to physical stress.

There also may be factors outside of the muscle cell that cause fatigue.⁶ Fatigue may be the product of an inability to activate muscle fibers, which is a CNS function.

A Neurophysiological Mechanism to Explain CNS Fatigue

Fatigue can be classified into electrophysiological and biochemical considerations. Electrophysiological involves steps in the CNS and the peripheral nervous system (PNS) or the fiber leading up to the binding stage of actin and myosin. In this article, I focus on the electrophysiological considerations on the CNS.

Davis and Bailey discussed the following CNS electrophysiological mechanisms that result in a reduction in CNS drive to the motor neuron:

• A reduction in the corticospinal (descending impulses) reaching the motor neurons—a reduction decreases the conduction of signals and impulses from the brain to the spinal cord and muscle.
• An inhibition of motor neuron excitability by neurally mediated afferent feedback from the muscle—inhibition hinders a motor neuron’s ability to be turned on (excited) because the brain is mediating the feedback retrieved from the sensory neuron at the muscle back to the CNS.

These considerations may involve a reflex where mechanoreceptors or free nerve endings give the CNS feedback based on the level of muscle metabolites present from the work the athlete is doing.³ Mechanoreceptors are sensory receptors that respond to mechanical pressure or distortion. Free nerve endings are unspecialized, afferent nerve fiber endings of a sensory neuron; afferent meaning bringing information from the body’s periphery toward the brain—they detect pain.

The CNS makes adjustments, regulating the maximal force that can be produced by the fatiguing muscles so a safe and economical pattern of muscle activation can occur. This is known as the sensory feedback hypothesis.³

There is good evidence that the perception of effort is strongly influenced by the magnitude of the corollary discharge (copy of a motor command) from the motor cortex that delivers information to the primary somatosensory cortex.³

For example, when the force that a muscle can exert is decreased via experimentation (by fatigue or with curarization), the perceived effort for the task increases in association with the more substantial motor command that a person must generate to achieve the target force.
“Whether or not these higher centers are modified by neural input from other brain centers, afferent feedback from the working muscle and/or changes in neurotransmitter metabolism subsequent to the passage of blood-borne substances across the blood-brain barrier is not well studied.”³

The Role of Neurotransmitters in CNS Fatigue

The job of a neurotransmitter is to transmit signals across a chemical synapse, such as a neuromuscular junction, from one neuron to another target neuron—the muscle cell. It also carries messages between cells in the brain and spinal cord.

Small sacs called vesicles store neurotransmitters, and each vesicle holds a single type of neurotransmitter. The vesicles travel like tiny little rafts to the end of the neuron, where they dock and wait to be released (presynaptic cleft). When it’s time for the neuron to release neurotransmitters, the vesicles dump their contents into the synapse gap (the space between cells) where they travel to specialized receptor sites.

In exercise and CNS fatigue, the key neurotransmitters are serotonin, dopamine, and acetylcholine.³

Serotonin

Serotonin is linked to perceptions of effort, lethargy, and CNS fatigue during prolonged exercise. It’s hypothesized that, during prolonged exercise, brain serotonin levels increase in response to increased blood-borne tryptophan (TRP) delivered to the brain. TRP is a precursor to serotonin.³ Because of the physiological conditions created during prolonged exercise, TRP circulates loosely bound to albumin, and the free TRP moves across the blood-brain barrier.³

Serotonin synthesis increases during prolonged exercise, which is associated with lethargy and loss of motor drive.³ When brain serotonin activity or TRP availability to the brain increases, fatigue from prolonged exercise occurs more quickly.

Dopamine

Brain dopamine synthesis also appears to be a key factor in CNS fatigue. It seems to be necessary for movement, and increases in brain dopaminergic activity may increase endurance performance. As noted by Davis and Bailey, dopamine may delay fatigue by inhibiting brain serotonin synthesis and by directly activating motor pathways. Dopamine increases neural drive as well as motivation.⁴

With ideal dopamine levels, athletes may want to train more and be hungry to compete. Share on X

With ideal dopamine levels, athletes may want “it” more. They may want to train more and be hungry to compete.⁴ Dopamine also seems to increase vasodilation and the sweat response. The general theory is: more body heat, better nerve impulse transmission.⁴ Consequently, CNS drive is enhanced and fast twitch fibers are reached due to their superficial nature.

Further Study for Speed and Power Athletes

The elusive question, though, is whether these hypotheses can be applied to all training stimuli and all populations.

• Fatigue of voluntary muscular effort is a challenging construct. It appears CNS fatigue is evidenced by a decrease in central drive likely involving accumulation and depletion of neurotransmitters in CNS pathways located upstream of corticospinal neurons.³
• As we move forward in understanding adaptation to physical stress, more efforts are needed to determine precise mechanisms of CNS fatigue that make biological sense of the perceptions athletes sense during training and the observations coaches make.
• Most of the work done so far has been in clinical settings (chronic fatigue syndrome) and using prolonged endurance performance models with athletes. Yet CNS fatigue is a term used in many other settings, such as the weight room and during sport-specific speed and power sessions. It’s also suggested that we can apply these mechanistic hypotheses to healthier, more adapted populations.

Perhaps the CNS simply lessens exercise intensity to more tolerable levels to protect all humans. Share on X

We are, in essence, examining the same biological markers and measuring CNS drive regardless of the population studied and the stimulus and stress delivered. Perhaps we just have different standards or normative data for the elite athlete versus those with effort syndromes, like chronic fatigue syndrome. Perhaps the CNS simply lessens exercise (stress) intensity to more tolerable levels to protect all humans.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

References

1. Asmussen, E., “Muscle Fatigue,” Medicine & Science in Sports & Exercise 11(4) (1979): 313-321.
2. Brooks, George, Thomas Fahey, and Kenneth Baldwin, Exercise Physiology: Human Bioenergetics and Its Applications, 4th Edtition (McGraw-Hill Education, 2004).
3. Davis, Mark, and Stephen Bailey, “Possible Mechanisms of Central Nervous System Fatigue During Exercise,” Medicine & Science in Sports & Exercise, 29(1) (1997): 45-57.
4. Davidson, Pat, interview by Derek M. Hansen, “Performance Concept Chat Episode 10: Exploring CNS Fatigue,” StrengthPowerSpeed,podcast audio, March 25, 2017, http://www.strengthpowerspeed.com/articles/.
5. Francis, Charlie, The Charlie Francis Training System (Amazon Digital Services, LLC, 1982).
6. Kenney, W. Larry, Jack H. Wilmore, and David L. Costill, Physiology of Sport and Exercise 6th Edition, (Human Kinetics, 2006).

 

In the strength and conditioning field, on top of lifting, jumping, and sprinting, there are myriad ways to influence performance outcomes. Many of these extras are technology-based, such as tracking velocity, forces, sleep, and recovery. One of these “extras” that I really like, but hear very little about, is electrical myostimulation, or EMS.

Most people know what EMS is, but I don’t see a lot of EMS use in the athletic community and, more specifically, in performance enhancement. I have seen it become more popular of late in high performance or CrossFit, but mainly from a recovery standpoint. I still don’t hear a lot of people talking about it from a performance/stimulus perspective. This is an area that I think holds a lot of potential.

I’ve been interested in EMS for a long time, after reading work from the Soviets, Paavo K. Komi, and coaches like Charlie Francis. It’s not like the research isn’t there—people have published it—but for several reasons, EMS is somewhat impractical in the field. If other coaches are like me, they find it difficult to isolate a single athlete in the training environment for the purpose of EMS. Since traditional machines have always been a bit cumbersome, and you can only use them on one athlete at a time, I think many coaches have written EMS off on an operational level, as opposed to a theoretical level. That being said, I think it can be a very smart investment for an elite athlete whose career tends to span over a decade when it’s all said and done. Although this article is focused on performance, most machines are quite robust and offer a multitude of benefits, for performance, recovery, and rehab.

Unanswered Questions

If you’re one of those coaches who has been curious about EMS but never made the jump, I’ll highlight some of my own experiences and the questions I had about it. My personal interest in EMS admittedly came as a spinoff from my early interest in the Central Nervous System (CNS). When I first began training athletes, I very quickly understood the limitations of the CNS to deliver high-quality output. What I mean by this is that you have a finite amount of “optimal work” that you can get accomplished before the athlete fatigues and loses access to their high threshold motor units. This is the period when they’re most recovered and primed/activated. This leads to one of the questions that frequently crosses my mind.

If my nervous system is such a limiting factor, would training the system with an external stimulus be counterproductive or would it be beneficial?

The data suggests there are many uses for EMS that would drive performance through many mechanisms. According to Komi (in his book, “Strength and Power in Sport”), many studies seem to be contradictory as to the results and mechanisms of EMS. However, in 2012, Filipovic et al. did a systematic review of EMS to try and find a clear-cut response on the effectiveness of EMS.

• This scientific analysis revealed that EMS is effective for developing physical performance. After a stimulation period of 3-6 weeks, significant gains (p < 0.05) were shown in maximal strength (isometric Fmax +58.8%; dynamic Fmax +79.5%), speed strength (eccentric isokinetic Mmax +37.1%; concentric isokinetic Mmax + 41.3%; rate of force development + 74%; force impulse + 29%; vmax + 19%), and power (+67].
• As a result, the analysis reveals a significant relationship (p < 0.05) between a stimulation intensity of ≥50% maximum voluntary contraction (MVC; 63.2 ± 19.8%) and significant strength gains.

Those results seem to indicate that there is a significant benefit to the use of EMS for performance enhancement—most notably, increases in maximal strength, power, and rate of force development. The fact that performance was enhanced is clear, the mechanism by which it enhanced is not so clear. This drew me to consider whether the EMS caused adaptations by itself or whether it merely facilitated more efficient work. My main question is:

Would pre-activating motor units with electrical impulses make them more excitable from an internal stimulus? Or does the EMS cause all the adaptations on its own?

The truth is, I don’t necessarily have the data to answer these questions. You might be better asking Carl Valle, as he’s written on EMS previously (see “The Top 6 EMS Protocols for Sports Performance”). However, I can say that I’ve personally experimented with EMS and have seen positive results.

Now, before I give you my personal experiences, let me tell you that this was a very casual experiment and would hardly pass the scientific validity test. My original purpose was mainly for fun as I had just gotten my hands on a high-quality unit and was curious as to the potential outcomes. I also used this on myself, as a coach and not one of my athletes. The reason I’m sharing this is just to give some feedback to people who are curious about it but never tried it.

Operating the EMS Machine

The first thing I learned is that EMS, at least for me, is progressive. I only used EMS on my legs and I used it mainly on “explosive strength,” in conjunction with my training. This utilizes incredibly strong contractions compared to a massage or recovery setting. The first few times I used it, the contraction I could handle was limited. As I improved my tolerance to somewhere between “uncomfortable”’ and “painful,” I could handle much stronger contractions, progressively. Thus, the technology probably has limitations depending upon an athlete’s level of pain tolerance.

Also, due to its progressive nature, my guess is that best results accompany prolonged usage. Besides this, operations are fairly straightforward: Make sure you have functional equipment and a comfortable position, since your EMS session could be anywhere from 20-40 minutes long. Then, pick the program you’re looking for and use the provided guide to place the electrodes in the appropriate positions. Depending on your brand of EMS, this could be a booklet, picture, or app. At the end of the day, the modern EMS machines are pretty simple. You don’t need to know the optimal frequency or time, as this has been simplified with pre-designed programs. Just plug the machine in, and pick your program.

My Personal Protocol and Outcomes

I know that many people use EMS systems to improve recovery and pain management, but I figured a piece of technology of this magnitude would be best suited for performance. I did a dedicated squat protocol and supplemented with explosive strength on the EMS (mostly quads, as they’re easiest alone) on training days. I figured there were plenty of ways I could work on recovery, but I wasn’t sure of other ways to send impulses through my system that were equal to or stronger than a maximum voluntary contraction. From a performance standpoint, this intrigued me.

Since I didn’t intend to publish data, I never set any controls and didn’t track my data that thoroughly; I only decided to write about this later. However, after about eight weeks, I was able to PR my back squat. The reason I think the EMS contributed to this is because I am nowhere near PRing on any of my other compound lifts, and my Olympic lifting is mainly attributed to technique improvements. Between my age and my training environment, I would never have thought that I’d actually hit a lifetime PR.

My training and EMS protocol followed three main squat workouts per week (I’m not including my accessory or upper body work here). Each of the three days would start with some Olympic lifting or Olympic lifting derivatives, and then went into the squatting soon after. It was never a significant amount of Olympic lifting volume—it was more of a primer than anything.

• On my first squat day of the week, I worked up to five sets of five.
• On my second squat day of the week, I worked up to five sets of three.
• On my last squat day, I worked up to a few doubles, then three or four singles.

Essentially, I went from volume at the beginning of the week to high load at the end of the week, but used auto regulation to find my numbers. I was fairly aggressive with the numbers I wanted, but I also never forced any and never failed a rep in training.

At night on these days, I doubled up and hit a quad program of EMS on either strength or explosive strength, with about 80-90% adherence over the six to eight weeks. I personally prefer explosive strength. I felt that by repeating on the same day, I could get a greater volume of work in after my nervous system had failed. Not only did I actively progress and overload with my training, but I tried to push with the EMS as well. Not that I recommend it, but I got to the point where I wore a mouthguard to bite down on when contractions became intense. All in the name of science.

I’m telling you all this to explain that I last managed to hit a 400lb back squat before my daughter was born, derailing my training once again. While it’s been almost 10 years since my football career, the EMS and training combination allowed me to hit numbers I thought were no longer within my grasp, due to my limited time and focus on training. I highly encourage you, if you have the right situation, to try experimenting with it yourself.

Although the EMS didn’t help with soreness, and I battled days of aching and tightness, I rarely had trouble increasing load by the time my body was sufficiently warmed up for the day. Between the combination of my own results and positive research, I definitely plan to continue experimenting with EMS on myself and a few of my athletes.

The Reasoning Behind My Conclusions

I’m sure there are other educators and maybe even coaches who can give better explanations of the mechanisms and outcomes involved, but I have my own guesses as to why EMS may be beneficial. I personally tend to think performance is driven more from the abilities of the nervous system than the abilities of the tissues involved, but I think EMS might possibly reconcile the two. I know I’ve personally seen compensations occurring, both in myself and in my athletes, and the inability to voluntarily activate specific muscle groups in a uniform way, during certain movements.

A clear example would be an athlete who is relatively strong, but if you asked him to do unilateral movements, he may lack the ability to activate or at least feel a strong contraction on one side vs. the other, either due to injuries or when seemingly “healthy,” if there is such a thing. For instance, asking an athlete with quad tendinopathy to do a single leg hip thrust—my guess is they won’t get much action out of the hip joint. I personally had issues with this even while operating at a high level (relative to my own maximal abilities). My belief isn’t clear, but if we’re inefficient at uniformly activating motor units and muscle fibers in training, EMS can stimulate an equal number of motor units on each limb relative to the amount of impulse being subjected to the area. Where I think this applies is probably (and remember, this is my opinion) through potentiation rather than tissue adaptation.

It is possible that the impulses can stress the local system enough to form their own adaptations, but I personally am not convinced that would be the case. My assumption, and take it for what it’s worth, is that intense uniform impulses probably make it more efficient at voluntarily activating those fibers in my own movements later on in my next training session. I personally only tested EMS in conjunction with training, not as a replacement for it, so it’s hard to say whether the EMS itself caused its own training adaptations.

As much as I feel like my training is generally guided by sound research, the contradictions and confusion with EMS make me want to continue to experiment on my own, as well. I feel that the downside has so far been minimal (or none), but the upside could be significant. I’ve already tested EMS with maximal strength and will continue to test it in more explosive ways, either with a jump test or sprint test.

If you’ve had success, or otherwise, with EMS, please share your stories and get some information out there! I’d love to hear about your experiences and keep pushing the boundaries of performance.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

 

Hi, I’m Ben Prentiss and welcome to PHP. I’ve just moved into this new facility after 17 years, 8,000 square feet of the world’s latest and greatest equipment. The latest and greatest piece that I’ve had for a year now, is the 1080 Quantum.

I’d say it’s an all encompassing, robotic game changer. That’s basically what I say because when people look at it they think it’s a Smith machine or it’s just a pulley, ’cause you really can’t tell when you look at it what it’s doing. But for me it really has been worth the price in terms of the amount we’ve used it and helped us do things that you cannot do. You can’t do. I mean that’s the number one thing is that there’s nothing out there that can do what the Quantum can do and that’s really it. I mean to overload, to use vibration, to use isokinetic, to boost eccentric, to go full speed, to be able to have the ability to throw or jump, there’s nothing there.

So it really gives the strength coach all of the tools in his toolbox, in one shot. Which trainers always say, “It’s great to have tools in your toolbox.” Well here’s one piece of equipment that basically gives you every variable possible.

One of the things that I like it for, that it’s not famous for is using in our structural phase, where we’re just using small muscles and people wouldn’t think of it as a huge selling point. But actually, when you ask any of my athletes, one of the things they hate the most, which means it’s one of the most effective is doing abductor/adductor, dorsiflexion, anterior tibialis, and rotator cuff, and trap three work. Is unbelievable for the effect. That we can use a two to one eccentric to concentric ratio and move at different speeds has really been effective for us.

Not only is the data important to show but the aspect of having each player sort of compete against each other and look at how much force they can produce, how much newtons they can produce, or how fast they can move the bar. All three of those things are hugely important in the game but also it’s important for the athletes to get better in season, which is a very difficult or typically a maintaining thing. Well now we’ve actually seen athletes through isokinetic get stronger in season.

So when I go back to dynamics with bands or dynamic squat with bands, or those kind of lifts. We’ve actually seen them produce more force after a phase in the 1080. So with so much success and I’ve had the 1080 for almost two years, two off seasons.

I’ve decided to get the 1080 Sprint. So it basically gives me the whole kitchen. I’m now able to do vertical and horizontal production and for me the most valuable tool would be to bring the 1080 Sprint on the ice. So I’ll be looking forward to giving a lot of info on that this coming off season

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

Sprinters in the north are no match for sprinters in the southern states. Why does Florida produce twice as many elite sprinters as Illinois? I think this speed differential has to do with sunshine and dopamine.

Dopamine is good stuff. With healthy dopamine levels, people are alert, happy, and feel an excited buzzing sensation of anticipation. I’ve had that excited buzzing sensation since listening to a Strength Power Speed podcast where Derek Hanson interviewed Pat Davidson. When I finished the 69-minute podcast, I tweeted what I had learned.

What Is Dopamine?

Dopamine is a neurotransmitter identified in the human brain in 1957. I remember my 7th grade science teacher explaining how neurons communicate. We were taught “Andy Axon sends a pass to Denny Dendrite.” The figurative football is a neurotransmitter. The space between the neurons is a synapse.

High dopamine levels provide many benefits to a sprinter including confidence, resistance to fatigue, and the ability to move fast.

High dopamine levels provide confidence, resistance to fatigue, and the ability to move fast. Share on X

In the podcast interview, Pat Davidson said, “Excessive dopamine can make you a lunatic; you can be crazy and psychotic if your dopamine levels are too high. I don’t know if that’s the worst thing in the world for athletes. Having an unrealistic belief in the supernatural and feeling as though they have powers that are excessive; that’s not the worst thing if I want a highly competitive person who thinks they can dominate and do things no one has ever done before. So, I might want excessively high dopamine levels. I don’t think I have a problem with that.”

Dopamine declines naturally from the age of 20 until the age of 80. I remember my excessive dopamine days very well. I was a confident risk-taker, feeling the invincibility of youth. As Pat Davidson said, “I don’t know if that’s so bad.” At the age of 58, I am realistic, well aware of my mortality, and I avoid risk. I thought it was maturity, but maybe it’s the dopamine.

Accomplishments make people feel good. Dopamine levels increase when we are rewarded. We like the way we feel so we seek more rewards. Yes, winning increases dopamine and then fuels the urge to win again. Success breeds success.

Winning increases dopamine and then fuels the urge to win again. Share on X

In Pat Davidson’s article for SimpliFaster, Central Fatigue, and the Role of Neurotransmitters on Reduced Work Output, he cited a 2008 study stating, “Enhanced dopamine levels will provide an increase in psychological motivation to work harder in a more stressful environment.”
Dopamine does more than affect your psyche. With increased dopamine, we experience an increased excitatory effect on our motor neurons and an accelerated velocity of limb movement. Not the worst thing in the world for sprinters.

How Do You Increase Dopamine Levels?

Actions

• Sleep, Sleep, Sleep. Nothing you do will improve dopamine levels more than sleep.
• Sunshine. Minimum exposure to sunlight should be 30-60 minutes, but the more, the better. Sunlight also increases the skin’s production of vitamin D, boosts testosterone levels, and improves the ability to sleep. We evolved for 35 thousand years living in the natural light. Too many people now spend their lives in artificial light.
• Meditation
• Massage
• Avoid junk food, especially sugar.
• Avoid excessive caffeine, including energy drinks.
• Limit exposure to blue light (bright screens including cell phones, computers, and televisions).
• Limit fluorescent light (go outside!).
• Avoid anything that provides instant gratification without effort or discipline. Instant gratification causes an initial spike in dopamine followed by a crash. Addictive substances like cocaine, nicotine, and alcohol spike and crash dopamine levels. Even behavioral addictions like gambling and pornography spike dopamine levels for the short term but have a negative long-term effect.

Nutrients

• Vitamin D
• Magnesium
• L-Tyrosine from natural foods including nuts, poultry, and fatty fish containing omega-3 oils (L-Tyrosine is the precursor of dopamine)
• L-Tyrosine supplements, 800-1,500 mg daily
• Vitamin B-6 (helps conversion of L-Tyrosine to dopamine)
• L-Phenylalanine supplements, 1000-1,500 mg daily (L-Phenylalanine is the precursor to L-Tyrosine)
• Fish oil or krill oil (omega-3 fatty acids) supplements

Medications

• Banned performance enhancing drugs like Adderall and Provigil (Modafinil); I once read about an athlete who broke a national record in practice while taking Modafinil.
  If nothing else, remember that sleep and sunshine are critical to maximize dopamine levels.

Do Sprinters Thrive in Sunshine?

Which states are best in high school track and field? The sunshine states. High schools in California, Texas, Florida, and Georgia dominate the national track and field rankings. Northern states like Illinois, New York, Pennsylvania, and Ohio are the second class citizens of the track and field world.

When northern coaches are asked why the sunshine states are so successful in track, their answers seldom mention sunshine. Their reasons include the following:

• Better weather allows for more effective training.
• California, Texas, Florida, and Georgia have more African-American athletes.
• California, Texas, Florida, and Georgia have better facilities.

There’s no question that practices are better under sunny blue skies, but many northern schools have indoor facilities. My high school has a 178-meter indoor track (nine laps to a mile). We have six lanes on the straightaway and four lanes around the track. We can host indoor meets, and our official track season is 19 weeks long.

There’s no argument, good weather is advantageous for training, but that’s assuming training is the key to elite performance. Egocentric coaches think dominant athletes achieve greatness from hard work and intelligent training. Enlightened coaches understand training is only a piece of the puzzle, and possibly a small piece. Training is overrated—important but overrated.

Is track more successful in states with higher African-American populations? At first glance, maybe. Based on the 2010 census, 11.4 million African Americans lived in the four biggest sunshine states (California, Texas, Florida, and Georgia). The four biggest northern states (Illinois, New York, Pennsylvania, and Ohio) had 7.8 million. However, the percentage of African Americans living in the northern states (14%) was greater than the percentage in the sunshine states (12%).

Equal numbers of African Americans (3.1 million) lived in both New York and Georgia in 2010. Based on 2016 track and field performances, Georgia dominates New York, especially in the speed events. What makes Georgia so much faster than New York?

There are no stats on track facilities from state to state. My impression is that Illinois track facilities are better than track facilities in Florida. I have no empirical proof to back up my opinion, but I’m sticking to it.

Speed, Endurance, and Strength

In my research, I went to Athletic.Net, a site ranks every athlete’s best performance from every state. I researched one sprint event (100 meters), one endurance event (1,600 meters), and one strength event (shot put).

Sprint Event

In the 100 meters, I found what I expected. The sunshine states dominated the northern states, producing nearly five times the number of sub 10.80 sprinters.

In the 100 meters, the sunshine states dominated the northern states. Share on X

The sunshine states had 771 boys running sub 11.00. In contrast, the cloudy states had only 195. The numbers running sub 10.80 were 294 to 60. The four sunshine states have a combined population of 95.6 million compared to only 56.8 million in the four northern states. The population advantage of 68% does not explain the 395% superiority in sub 11.00 sprinters and 490% superiority in sub 10.80 sprinters.

Endurance Event

After finding what I expected to find in the sprint event, I was surprised by what I found in the 1,600-meter endurance event. The sunshine states, per capita, are no different than the cold, cloudy, rainy north, where distance runners do months of training in the ice and snow. The sunshine states had 170 sub-4:20 milers, the northern states a respectable 103. The 65% more sub-4:20 milers reflect the 68% population advantage.

What? Is good weather training only important to the speed events? Is sunshine more important to sprinters than milers?

Strength Event

So what about the shot put? California, Florida, Texas, and Georgia had 87 shot putters who achieved marks over 55’0” while the north had 76. This 14% advantage is negated by the 68% population advantage.

Let’s recap.

• Track athletes in the sunshine states are fast, really fast. Sprinters in the north are no match for sprinters in California, Florida, Texas, and Georgia.
• Endurance runners are essentially equal in good weather and bad weather.
• Shot putters training in cold-weather states are as good, if not better than, shot putters who throw in the sunshine.

How can Florida produce twice as many elite sprinters as Illinois, while Illinois produces twice as many elite distance runners and throwers? Track and field is considered superior in Texas, yet their only advantage is in the speed events. How can California have seven times more people than snow-covered Wisconsin but only produce twice as many elite shot putters?

I believe the answer is sunshine and dopamine.

Marcellus Moore

I have a sprinter on my track team named Marcellus Moore. Marcellus finished the indoor season ranked IL #1 in the 60 meters and the 200 meters, running 6.86 and 22.13 respectively. These numbers are incredible considering Marcellus is only a freshman who won’t turn 15 until June 30th. When I think of age 14, I think of an eighth grader.

Our school has spring break between the indoor and outdoor track seasons. This year, our spring break lasted 12 days. We usually give sprinters the entire week off since track season is 19 weeks long. Because the break was longer than usual, we practiced on days 10, 11, and 12. Our practices were low-volume and totally alactic. Before the break, I warned Marcellus not to spend his spring vacation doing massive workouts. I explained that he needed rest, recovery, and growth—not hard work.

With a big smile, Marcellus replied, “Don’t worry coach, my family is going on a seven-day cruise.” Marcellus returned from his cruise, practiced three times, and then traveled four hours to the first outdoor track meet of his high school career.

He won both sprints and broke both of Plainfield North’s sprint records, shocking the track and field world with times of 10.55 and 21.28 in the 100 and 200, respectively. Good times for a kid who could be an eighth grader.

Was it the rest, recovery, and growth that produced these elite times?

Was it the low-volume, high-intensity training at our three practices?

Or was it the Caribbean sunshine?

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

Disclaimer: I love the squat and I love deep squats. I come from a powerlifting background and feel a deep sense of pride that I would miss squats rather than cut them high. This was my sport, and I took great pride in my sport. Some say that I hate deep squats, but that isn’t it at all.

I just happen to think that things that are great for one sport aren’t great for all. I’ve gone on record many times as saying that we don’t need perfect technique on Olympic lifts. Reasonable is good enough and, in fact, I mostly just did pulls with my athletes. Likewise, do we need to have a powerlifting standard for squats? Food for thought as we go ahead. Many will disagree, and that’s OK, but I feel that we need to get this information out there now rather than later.

Introduction

If we remember back to the classical periodization models, we see that they were listed out in very general terms. There was Volume, Intensity, and Technique, and that was all. When looking at the Volume and Intensity lines, I think that current strength and conditioning practices are fantastic. Most coaches start with a higher volume and lower intensity (percentage of 1RM) in the off-season; during the pre-season, they decrease volume and increase intensity (percentage of 1RM); and then during the competitive season, they keep both volume and intensity (percentage of 1RM) to maintenance of gained levels.

However, I think there are some areas that we can improve or we have possibly misinterpreted. It is not uncommon for something to be lost in translation. For instance, we have colloquialisms in our language, and they don’t translate into other languages very well, as I found out in China. We had our nomenclature and applied the Soviet nomenclature to it. The Soviet literature had two phases: GPP and SPP. Intensity, from talking to others who speak and translate from the Russian language to English, was more about the quality of the movements and how specific they were. While percent of 1RM absolutely plays a part in it, it’s less important than the exercise.

Was technique referring to sport skill only, or did it also relate to transfer of training for the weight room? For example, in some of Vherkoshansky’s work¹, he changed from squat to squat jump or some other exercise, and didn’t maintain the squat from block to block. He went from a general exercise to what he felt was a more specific exercise for his athletes. They progressed their types of jumps from extensive long coupling to intensive short coupling over time. They didn’t just change the type of movement, but changed the movements themselves. For instance, they went from steadier, coordinated bodyweight squat and tuck jumps to drop jumps and bounds over the course of the training cycle.

History Lesson: How to Apply the Work of Matveyev and Bondarchuk

Before continuing, I think it wise to note that at no point are any of the three variables ever at zero in Matveyev’s chart². What this indicates, at least to me, is that there is a small portion of everything in at all times, but the emphasis is switched. This was confirmed to me by Doc Yessis and Anatoliy Bondarchuk about the typical Soviet programming, and the proportion they gave was that there is typically an 80/20 split during the GPP phase of 80% general exercises and 20% specific exercises. This made a gradual shift to the SPP phase, which ended up being 80% specific exercises and 20% general exercises.

One area that we could do better on is the alternation of exercises through the course of the year to elicit greater gains. A recent study by Rhea et al.³ showed that the ¼ and ½ squats had better transference to the sprints and jumps than the full squat. There are two groups that read this article: The first group has cut out full squatting altogether and only does ¼ and ½ squats to have greater transfer; and the other group calls it heresy, wants Matt Rhea, Joe Kenn, and the other authors all burned at the stake, and refuses to think for a second that the almighty ass-to-grass squat may not be the best thing.

How the Standard of Squatting Was Determined

An interesting side note, and a question no one ever seems to ask, is: How did the crease of the hip below the knee/top of thigh become the standard of squatting? I have unique access to information such as this, as I often lift in Bill Clark’s gym. Bill Clark is the last remaining member of the three-person committee that started “powerlifting” as an offshoot of Olympic lifting, and I talk about this in a section with him in my book, “Powerlifting”⁴. I asked him this question and I’m paraphrasing his answer. (If you’ve ever spoken with Bill, a two-second question can garner a two-hour answer.) “Well, we needed to have criteria for what made a good lift. For deadlift, it was easy. You stand up with it. For bench press, it was easier than the squat. You go down, touch your chest, and come back up. For the squat, it was a bit more abstract so we chose what seemed to make the most sense—the crease of the hip and the knee. If you went below that, it was a good squat because you went low enough. If you didn’t, it wasn’t.”

Ole Clark, as he is affectionately known around here in mid-Missouri, is a stickler for squat depth, as well he should be. However, has our love affair with squat depth as the crease of the hip below the knee, which came about as a compromise between three people for a rule, become the reason for the ass-to-grass squat? I’m not completely sure, but I started in S&C from a powerlifting background, and I know many of us in S&C have. This is where my viewpoint on the squat came into play, and I made everyone squat to depth because that was the standard.

My Evolution in Strength and Power Training

Before moving forward, I want to point out my own fallacy. My athletic background is as a powerlifter. I still am addicted to strength and heavy loads even though my body is broken down. So please don’t take this as a “he’s an anti-strength guy and all single joint specificity guy blah blah blah, yada yada yada…” Take this as a “been there, done that, bought the T-shirt,” guy who is trying to help others learn from his mistakes.

When I started out in this field, I looked at everything from the viewpoint of the squat, bench press, and deadlift. Admittedly, I tend to track back to that every now and then (full squat and deadlift 1RM), but I looked for ways to make the squat more effective for longer term periods, and really expanded into velocity-based training from that. We would squat for strength and for strength-speed. When that was done, we saw greater power and speed gains over the longer time period of the course of their career, but there was a limit.

Managing Complex Training Variables

Where Jacobson et al.⁵, and Miller et al.⁶, found the gains of squat transfer-to-power extend for one year, we had them extend for three years⁷, with the second and third not being anywhere near as steep as the first. This may be partially explained by the use of velocity on the squat and the use of accommodating resistance (chain, in our case) during training⁸. The gains did stop, though, before the fourth year, and on average we did not see any improvements at all. What would have happened if we would have periodized the exercises, rather than the velocity/intensity? I’m not sure. Would moving away from the squat for a while have had a beneficial effect on the athlete? Possibly, but I’m not sure. What I do know is that altering the squat from strength had a beneficial effect.

For a moment, let’s go with an open mind and look to apply the findings of Rhea’s study³ to the original Matveyev model. If we remember that the purpose of the GPP phase was to restore and increase general qualities such as general strength, mobility, and work capacity, we see that the full squat absolutely checks those off the list. As we gain in strength, mobility, and work capacity, and hopefully power, as a result of this, we are fulfilling the purpose of GPP, and thus, this is the appropriate time to utilize the squat. If we then think of the SPP phase as using specific exercises, we can utilize the ¼ and ½ squats most appropriately at this time. The study showed that trained athletes had the greatest transfer to the sprints and jumps, which fulfills the requirements for SPP.

Now, some people may question about the transfer of the ¼ and ½ squat to the jumps and sprints, and that’s fine. Let’s look at some pictures of an elite level sprinter and go into more detail.

If we examine Image 2, let’s look specifically at his drive leg right now. Some folks on Twitter looked at an image similar to this one and said, “See how high his leg is? That looks like a full squat to me.” While I will agree on the hip and knee flexion angles being representative to the squat, how did he get there? Did he get there by lowering his center of mass until he got to this position? No. He went through a violently rapid hip flexion and drove the knee forward to get into that position. Try doing that on a squat—let’s see what happens if you drive one or both knees to your chest and in front of you from the beginning of a squat.

My point is that, if the squat is done in this manner, the individual will either a) dump the bar or b) land on his tailbone. It’s not simply the picture of what someone achieves, but how the person got there is extremely important as well. The hip extensors working eccentrically or the hip flexors working concentrically to achieve hip flexion are two very different activities.

Some will say it’s about the drive from the thigh moving downward to the ground. While there is acceleration downward from the thigh from the hip, it’s unimpeded until the foot makes contact with the ground. At the point when the foot meets external resistance (the ground), the squat strength takes over. Before the increased force production due to ground contact, the majority of force production comes from the sarcoplasmic reticulum. The sarcoplasmic reticulum’s release and re-absorption of calcium enables the actin to be released for the myosin to grab a hold and pull the actin towards it. This allows for the rapid contraction utilizing the sliding filament theory of muscle contraction.

If we examine Image 3, we’re in the stance phase on the right leg, with the left leg going into the drive phase during the accelerative portion of the sprint. As a side note, Dr. Michael Yessis would tell you this is an example of great technique⁹. If at this point in the sprint you see two calves and one thigh, they’re doing it right. If we examine the right leg during this phase, we can see that the right leg is slightly bent during this portion of the sprint. This is going to be one of the deepest portions of the sprint outside of coming out of the blocks that the knee will bend. How low is his squat? I’d say it’s probably around a ¼ squat. During the sprint, there is no full squat.

Breaking Barriers in Exercise or Training Bias

I think that we have allowed ourselves—myself included—to become married to certain exercises; to say that this exercise is the foundation of our program and we should never move away from that. This reminds me of the railroad industry. They have since fallen on hard times, but at one point in our great country, they were the king. They felt that their job was to put railroad tracks down and put trains on them, and move people and products across the country. When the automobile came along, it made the railroad obsolete because people could go anywhere they wanted on the highway system and were not constrained to their routes and locations. The railroad then fell to a point that, while it is still a great industry, the giants of yesteryear no longer exist.

If we stop favoring certain individual exercises, we may improve the results we get with athletes. Share on X

If we say our job is the squat, the hang power clean, and the bench press, and that is what we will do come hell or high water, is that the best thing for our athletes? If it has worked for decades for building athletes (one to two years at a time), it should be in. Well, it hasn’t worked. When it has been done in Division 1 athletes^5,6, the research is clear.

If we re-examine ourselves and cut our ties with individual exercises, we may be able to enhance the results we get with our athletes. If we change our viewpoint on this and look in terms of what is most specific for a certain sport/event/position within a sport, and apply this at the appropriate time, then we can look to cause the greatest transfer. We must remember that in no sport is there a barbell involved, other than powerlifting, strongman, odd lifting, or Olympic lifting. Even for those, odd lifting and strongman often don’t use barbells. Because of this, the training choice should be based on transfer of training rather than the increase in a 1RM. This does require a paradigm shift, but one that I think is quite beneficial. We remember from Zatsiorsky¹⁰ that transfer of training can be determined by the following equation:

Transfer of training = Result in event/result in trained exercise

At this point someone will say, “I have a team sport, so that’s not possible. I’m going to continue what I’m doing.” While it’s true that this is more difficult in team sport, we can’t say that the performance in the weight room was related to the sport. There are too many confounding variables. We can’t account for the other team, the interactions between team members, the play calling by the coach or individual on the court, or even the environmental factors like the crowd. We do know that we have certain metrics that are predictive of abilities for sports, which are often called Key Performance Indicators (KPIs). For instance, jumping has been shown to be predictive of excellence in volleyball and basketball. For football, it’s been found that the standing long jump is a great predictor when combined with sprint and agility tests. In these cases, when we look at the result in the KPI and divide that by the result in the trained exercise, we can get a great example of where we stand.

If we look at the work by the great Soviet hammer coach and medalist, Anatoliy Bondarchuk, we see that every time they went through the adaptation process, he changed every single exercise. He did not leave one exercise in because it was his anchor. (In this example, I refer to the GPP, SPP, and SDE means. He would keep the throws in, but even then, it might be competition weight, or slightly heavier or slightly lighter)¹¹. Every cycle was entirely new and stay entirely the same until they went through the adaptation process, and then everything changed again¹². He would track and know what exercises had the greatest transfer for the throwing event, and even the athlete. When it was time for a key competition, he would put in the exercises that had the greatest transfer to the event/athlete.

If we re-examine our terminology and look intently at the term “quality,” it may start to help make sense of some things. It allows us to not view things in terms of 1RM, but in terms of how closely it ties into the sport, and how close it transfers. It may not replicate a portion of the sport, but that’s OK. It’s all about the transfer to the sport itself.

So, let’s look at the squat. Once we enter the SPP or pre-season phase, if we alter the back squat to a ¼ squat for a block of training and then a ½ squat for a block of training, we are giving two different stimuli that have a higher transference to the sport. Once we go through those, we may switch back to the ¼ squat and alter it with either an accommodating resistance or a change in bars. We may possibly even change to a lower box step-up for something else that allows the body to re-stabilize and go back through again.

Here is an example of what this may look like:

Many people tend to argue against periodization and say that it’s dead. Then they’ll talk about how they alter from more general to more specific exercises over the course of the year as they move into their season. Having a plan and changing to more specific from more general is periodization. What we must remember is that periodization doesn’t mean doing x sets times y reps at z intensity; it is a plan of what will be done and when for a period of time. Interestingly, this means that many of those who argue against periodization are actually arguing against one form of programming. This is great: We all agree that there needs to be planning, but we argue about what the best plan is.

This is only an example of one exercise. Let’s say, for instance, that over the course of the year we find that the mid-thigh power clean has the greatest transference to the sport we happen to be playing. Is that saying that we don’t ever do the other variations? No. Absolutely not. What it says is that, during the SPP phase, the mid-thigh power clean is our go-to, especially for when we are moving in to what may be the championship. There will be many exercises that have better transfer than others, just do them at the appropriate time.

You may start thinking that all training should be based upon specificity. In certain models that would be fine. In Anatoliy’s models of periodization, everything is in all of the time—meaning that GPP, SPP, SDE, and the competitive exercise are in at all times. You’ll notice that it’s not SPP only, but that GPP is also included at all times. For more traditional models, the GPP phase needs to be there. This will help to prevent injury, and by increasing the strength and size of the GPP overall (strength, mobility, robustness), you seem to increase the SPP’s receptivity for adaptation.¹

Some people will read a study like this and think that it’s telling us that all we need to do is SPP, so that’s all we are doing year-round. This is a mistake with the reader’s interpretation of what the authors are saying. (I know because I asked them.) The study shows that there are squats that are general and there are squats that are more specific. Both types of training (GPP and SPP) are needed, regardless of the periodization model you utilize. Even Bondarchuk, who is famous for specificity, included GPP in his program year-round. (SPP and even more specific types of training, such as the competitive exercise and Special Developmental Exercises, were included).

Why does the GPP phase need to be there if it doesn’t have as great of a transfer then? First, while it wasn’t as great, the authors clearly stated better transfer; they didn’t state that the squat didn’t transfer at all. Second, the phase does have a great amount to do with mobility, injury prevention, and base strength. These are all quite important qualities. The more mobile the athlete is and greater their base strength is, the greater they can push the SPP and, thus, achieve higher transfer.

There has to be balance, and when training is out of balance, so are the results. Share on X

One thing that I think we constantly do wrong is that we tend to overcorrect. As VBT has increased in popularity, people have started doing everything with it. As functional training came into vogue, every exercise was done on a Bosu, Airex, or Swiss ball. As power factor training came into vogue, every exercise was done as a partial. Balance is required for training—if we look back at the physiological aspect, we see that we can have adaptations to the Series Elastic Component (SEC) in the following ways¹³:

• To the muscle cell in terms of myofibril adaptations by increasing heavy chain myosin size (and the ability to increase its strength of holding onto the actin or resisting breaking apart from it); and
• Increases in the efficiency of the sarcoplasmic reticulum’s ability to absorb and release calcium, which allows the actin and myosin to interact with the troponin unlocking the receptor site for the tropomyosin to move and the actin to be grabbed.

Then two neural means are:

• Henneman’s size principle, where high-threshold motor units are preferentially recruited; and
• Rate coding, which deals with the speed at which the inter and intramuscular coordination aids in muscle contraction velocity.

There has to be balance, and when training is out of balance, so are the results.

One question that you may be asking right now is: “Where do I get more specific exercises?” I’d like to point you in the direction of two authors. The first is Anatoliy Bondarchuk, whose books, “Transfer of Training in Sports” and “Transfer of Training in Sports, Volume 2” had a great number of exercise charts showing how athletes responded to various exercises in the throws. For an interesting read, also check out his critique of the Soviet methods to see his views on their periodization models. The other is the work of Dr. Michael Yessis, who developed special exercises for the sprints and jumps. (Interestingly, he did push the ¼ and ½ squats in favor of the back squat for adaptation to the sprints and jumps, more than 30 years ago.) His books, “Build a Better Athlete” and “Biomechanics and Kinesiology of Exercise,” both contain a great number of special exercises with descriptions, pictures and their applications.

These two men, as authors and practitioners, have had a profound effect on the way I view training athletes. Specialized exercises are any exercises that elicit a greater transfer to the sport. There will be a large amount of carryover for exercises among sports, but there are also some sports that have specific exercises that are different.

Specialized exercises are any exercises that elicit a greater transfer to the sport. Share on X

In conclusion, there needs to be a great amount of balance in a program. We must realize that there are multiple ways to produce force, and ensure that all of these are being trained. We must realize that, when you focus on only one thing, something else will fall off. If we only do the general and negate the specific, we tend to not have as high end results. If we only do the specific and negate the general, we tend to get injured and not have as high results because there is no platform upon which to stand (GPP).

Again, while the ¼ and ½ squats do have the greatest transfer, the time to put them in is during the SPP phase of training (pre-season), as this will have the biggest impact on sprinting and jumping performance. The full squat should be done during the GPP phase of training (off-season), as this will have the biggest impact on mobility and general strength.

Not one of the variants is “better” than the other for the body. Rather, there are just times when it is better to do one of the variants over the others. All are needed; the question is when and where to put them for the greatest effect on the sport.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

References

1. Verkhoshansky V and Verkhoshansky N. Special Strength Training: Manual for coaches. Rome, Italy: Verkhoshansky.com, 2011.
2. National Strength & Conditioning Association. Essentials of Strength Training and Conditioning. Champaign, IL: Human Kinetics, 2000.
3. Rhea MR, Kenn JG, Peterson MD, Massey D, Simão R, Marin PJ, Favero M, Cardozo, D and Krein, D. Joint-Angle Specific Strength Adaptations Influence Improvements in Power in Highly Trained Athletes. Human Movement 17: 43-49, 2016.
4. Mann B and Austin D. Powerlifting: The complete guide to technique, training and competition. Champaign, IL: Human Kinetics, 2012.
5. Jacobson BH, Conchola EG, Glass RG, and Thompson BJ. Longitudinal Morphological and Performance Profiles for American, NCAA Division I Football Players. The Journal of Strength & Conditioning Research 27: 2347-2354. 2310.1519/JSC.2340b2013e31827fcc31827d, 2013
6. Miller TA, White ED, Kinley KA, Congleton JJ, and Clark MJ. The effects of training history, player position, and body composition on exercise performance in collegiate football players. Journal of strength and conditioning research/National Strength & Conditioning Association 16: 44-49, 2002.
7. Mann JB, Sayers, Stephen P, Cutchlow, Rohrk, Mayhew, Jerry. Longitudinal effect of traditional and velocity-based training on vertical jump power in college football players. Presented at NSCA National Conference, New Orleans, LA, 2016.
8. Rhea MR, Kenn JG, and Dermody BM. Alterations in Speed of Squat Movement and the use of Accommodated Resistance Among College Athletes Training for Power. The Journal of Strength & Conditioning Research 23: 2645-2650. 2610.1519/JSC.2640b2013e3181b2643e2641b2646, 2009.
9. Yessis M, PhD. Build a Better Athlete. Terre Haute, IN: Equilibrium Books, A Division of Wish Publishing, 2006.
10. Zatsiorsky VM. Science and Practice of Strength Training. Champaign, IL: Human Kinetics, 1995.
11. Bondarchuk AP. Ypsilanti, MI: Ultimate Athlete Concepts, 2007.
12. Bondarchuk AP. Champion School: A Model for Developing Elite Athletes. Ypsilanti, MI: Ultimate Athlete Concepts, 2015.
13. Haff GG and Triplett NT. Essentials of Strength Training and Conditioning 4th Edition. Human Kinetics, 2015.

I work with some of the best coaches internationally, and we get into both macro and micro conversations related to practical and meaningful feedback metrics. These in-depth conversations include a lot of “why’s”: why do we and why don’t we. With the increased buzz and adoption surrounding the various technology options for Velocity-Based Training (VBT) used with the barbell, I think we are overdue in exploring a lot of “why’s.”

From my perspective, much of the way VBT tech feedback is utilized today is rather stale, uncreative, and possibly not very transferable. More and more coaches, at all levels, are hungry for VBT tech solutions—seeking to improve outcomes—yet today’s mainstream guidance is dated. The majority of questions related to barbell tracking technology that I get asked by coaches were already answered in the 1980s. This is certainly not a knock on those coaches, as if you do not know you need to ask; rather, the thing that is troubling is that the answers have not changed.

We have seen the most progress for barbell tracking in the recent and rapid evolution of the technology: wireless and ultra-portable sensors that report to apps sitting on smart devices. The result is a significant reduction in cost to the coaches, which opens the door for wider adoption because cost is no longer an issue. This is great. With less-expensive options now available, and systems that utilize the smart device you are already carrying, the technology progression makes a lot of sense.

The fresh sport tech options have no doubt increased buzz around barbell tracking, but we need to be cognizant of conveniently blending the new tech with the old methods. I understand your intent in using VBT tools and methods to develop better athletes. Since you are taking the time, spending the often-limited resources, introducing change, and putting in a lot of overall effort, my plea is a simple one: Read our scientific and coach-friendly argument to train with a purpose instead of training within potentially flawed fundamentals.

As the founder of my company, I knew that we had two paths to choose from: (1) roll into what is popular to get quicker sales; or (2) build for those that are aware of the true needs of athlete development. The second road was clearly going to be tougher—a longer and bumpier road in terms of product development and market acceptance—but it’s worth it now, as coaches are understanding the “why.” We chose to design a system that provides professionals with the right information delivered in a way that makes training better, and not hampered by too many steps or a time burden.

Please understand, this is all a balance, and many pros and cons are evaluated. What I share may ruffle some feathers and may make some coaches and even some sports scientists uncomfortable. But I am committed to ensuring the improved solution is available for those in the iron and athlete craft. Our product development goal and vision is to offer what you know and understand, while leading with innovation.

Are Speed Zones Obsolete and Just a Dead End?

There are often two primary mistakes made with training with velocity: (1) training at specific speeds for the purpose of hitting strength qualities, and (2) training to optimize power within the force velocity curve. I will explain why we moved away from speed zones and why the promotion of excessive force velocity by social media needs to simmer a bit. Reaching a peak or average speed on a snatch or clean is not overly meaningful without the load of the bar being relative to the athlete’s bodyweight. Barbell velocity hits a terminal speed barrier from the mechanics of many exercises, including most Olympic lifts where coaches use VBT tools to measure. Terminal speed is represented by the metric peak speed, the point of the movement where acceleration essentially hits zero, and the bar is no longer accelerating or gaining speed.

The promotion of excessive force velocity on social media needs to simmer down a bit. Share on X

Due to the specific timing sequence of weightlifting exercises, bar speed doesn’t provide room to hit sufficient-enough velocities to be meaningful beyond successful attempts or an indication of just using a lighter load. Put simply, a light and heavy clean or snatch will not vary much in velocity because of the technical limitations of the exercise, so slightly faster or slower speeds will not mean anything beyond the athlete selecting a different load on the bar. Mladen Jovanovic fully explains this in his roundtable discussion when he outlines the difference between open- and close-ended exercises, namely the jump squat and Olympic-style exercises. In summary, bar speed for Olympic lifting is important to keep the athlete sharp, but the exercise speed range is much more narrow than coaches are aware.

Video 1: This video showcases how the Bar Sensei stacked up to the Tendo and Push Band while I was at a local university. Speed zones are an OK starting point, but most coaches really want more speed or more load in training.

Bar speed does matter, no doubt, with the intent of bar velocity being essential during lifts that help drive power down the road from greater gains in maximal strength. Much of the improvement in power comes from low-velocity lifts that recruit more of the “high threshold motor units,” and those lifts are slow, such as heavy squatting. Other activities that are much faster, like plyometrics, are significantly more rapid than barbell exercises. When the movements are unloaded, coaches often prefer to do those actions on the field and save VBT for heavier weights. Barbell velocity should be about selecting the right load with the right exercise in order to get a desired training effect in activities that team coaches want results in on the field or court.

Earlier in the article I mentioned how most coaches ask me the same question. To elaborate more, that question is related to average zones and, often, on applying these zones to Olympic lifts. Whether the question is centered around Olympic lifts or a squat, I ask “Why are you interested in average versus peak?”

Bryan Mann is currently doing a great job migrating coaches away from the earlier suggested average velocity ranges to peak velocity ranges. We would like to see the coaching conversation evolve from simply recording a bar speed/hitting a zone target, to asking questions like how (or which) barbell metrics transfer to body performance.

Unless you are a competitive bar speed lifter, isn’t transference what we are really trying to get at? By displaying how specific measurements of exercises help transfer and identify improvement from training, coaches are more empowered to make decisions that really show up later in sport, not just on weight room record board walls. Like coaches in the past understanding the balance of blending maximum strength into power and speed training, we are concerned about the carryover to athletic actions.

Barbell Measurements That Matter for Sports Performance

When we develop a product, we work backwards, anticipating the user needs and working them into the technology platform (there are many layers to this). The same holds true for performance enhancement: work backwards, understanding athletic actions and seeing what is necessary to improve those abilities. Approaches often start with strength and power training and forcing a hit-or-miss agenda with concepts that might make an athlete test better in the weight room, but the results may not show up outside of the complex. Coaches that chase a certain barbell measurement will inevitably get frustrated later when that training “improvement” does not manifest anywhere in the game or event that the athlete competes in. Whereas, when using the right metrics package, coaches can hone in on the right movements, the right overload, and the right timing to stress the system.

We certainly provide legacy barbell measurements like average and peak velocity, and estimated force and power values, as they still have a place, but we are committed to providing a better measurement menu to coaches and athletes.

Mean Propulsive Velocity (MPV): In the research, a braking force occurs with some movements at lighter velocities. If you do not plan to jump, you “force” yourself to slow down. Even at heavier loads where the research backs acceleration throughout the full range-of-motion (ROM), our field data collection from elite power lifting shows this isn’t always the case. Advanced athletes consciously don’t lock out a rep, as they fear hyperextension or, if they are squatting, don’t want barbell rapid compression on the upper spine. As the loads get more and more impressive, including the speeds performed, the technique changes from what we typically see at lower level athletes who are using much lighter loads and sometimes even a Smith machine.

The bottom line is that different athletes move weight a different way, and we all know that. There are explosive lifters and there are grinders. That is why speed and power zones based off a percentage of 1RM really bug me. The art of coaching is determining the demands of your athlete and getting them trained to the right place. MPV is not a replacement for peak velocity; it acts like a watchdog to technique variance that will sometimes occur with unique training circumstances.

RFD (POP-100): Rate of Force Development is not very reliable in some sport actions. It is a moving target, and a controversial measurement due mostly to the procedures of the test. The conversation around RFD has turned it into a wide-open term, as most people do not understand its true definition, making it a complicated metric. But the context of what RFD represents to sport transfer is important, as the most explosive athletes are not always differentiated via full ROM metrics.

Finding a reproducible time frame within the movement to display results is key. Enter POP-100, defined as the speed produced at the 100-millisecond point of the concentric phase. Whereas Athlete #1 and Athlete #2 record a very similar full ROM peak bar speed for the squat, Athlete #2 has a 40% greater POP-100. Who is the explosive athlete? Using pin press exercises (squat, pulls, and bench press variations—coming very soon) in combination with POP-100 creates a firm starting point to test the rate of force generation trends.

Distance: One area that is neglected with bar tracking technology is joint angle estimations. A quarter squat may have sport-specific connections, but without knowing how deep one is, making a comparison is nearly impossible. The distance (or displacement) of any defined squat depth (1/4, half, parallel, full) will vary among athletes. Reinforcing full range of motion, consistency, and even exploiting sport-specific joint angles are all possible when distance of motion is measured.

We estimate distance from careful calculations, and the data is precise enough for solid decision-making in real-world scenarios. In addition, once the athlete learns their intended squat distance, the instant rep-by-rep feedback keeps them honest. As we refine our algorithms for higher levels of precision, coaches and athletes can start adding another level of evaluation with popular training lifts.

Eccentric Action: Popular outputs like peak and average force, velocity, and power are all concentric scores of movement. While I thankfully sense, by attending conferences, that eccentric training is growing in understanding, rarely does the VBT discussion come into play. Rather, the conversation still sits on counts, which are often deliberate and slow.

If you want your concentric values to improve, consider VBT applications on the eccentric side. Share on X

Eccentric training isn’t about speed in isolation; it is about overload and how speed is lost or gained later. Eccentric strength is very specific and a priority to coaches, and it is limiting to only look at the contributions from concentric actions. In fact, if you want to see your concentric values improve, consider VBT applications on the eccentric side.

Composite metrics, or combined measurements, will come down the road eventually, and exporting these aforementioned measures can further inform the coach and sports scientist of the true cause and effect of training. As the science evolves, my team and I will explore these opportunities, provided they are practical to coaches in the trenches. All of the above-mentioned measurements center around being a guide to help the coaches achieve human performance improvements with their athletes, not just as a means to collect barbell movement numbers.

Surgical Repetitions and Valid Measures in Training

In 2007, when I was hired by Myotest (in the pre-smartphone days), bar velocity was just starting to gain mainstream traction, and the measurements of more complex movements like jumping were more popular. Randy Huntington, a USATF Master Coach, used the Myotest to creatively evaluate very demanding bounds (hurdle jumps) with Olympic-level jumpers. The project we worked on together to fuse the force curve into the video was a big eye-opener for my education.

Here was a guy applying this brand-new tool in his own manner to analyze the muscle stiffness of athletes. This kind of blew away the value of vertical jump testing; drilling down into what really counts. I had recently transitioned from the medical device space—surgical precision is where I came from and what I wanted to bring to coaches. After seeing this surgical breakdown to get at stride-to-stride muscle stiffness, I caught the bug.

Yet, what was happening in the majority of sports was just the opposite—a lack of precision with the technologies and a lack of movement discipline during the assessments. There were many ways to cheat the tests, and the athletes were well aware of them. Without getting into the engineering details, some of these testing products flat out had way too much variability introduced by movement technique differences, while others were too loose in function to simply provide a number over data efficacy. Is the number valid and/or precise and can we trust the data?

Most of the challenge of calculating barbell performance is knowing the exercise in infinite detail, not using statistical modeling or other convenient ways to get estimates quickly. A lot of testing is required, as well as defining what a repetition truly is. Coaches badly want each repetition to be measured, but the system is looking for what it is programmed to pick up. We certainly are not perfect, but most of the coaching comments about the system “missing reps” are due to user error, not the technology. There are the issues of following the movement instructions, and the intended use of the product, along with proper execution of the lift. For example, during the deadlift the system is expecting the concentric phase followed by a lock-out. If you start the lift but don’t lock out, the system errors the rep and resets for the next one.

My job is to dissect a repetition and know when the sensors need to measure and when the motion is not to be counted. This is the hardest part of developing a bar tracking device. A box squat to an accelerometer is radically different than a jump squat, but detecting the difference between a quarter squat and racking a heavy full squat often results in some sensors adding a false rep, commonly referred to in some circles as the “phantom rep.”

Missing reps are not the fault of the sensor; it’s usually the sensor being so precise that a few centimeters of motion are lost, so it doesn’t count the rep at all. Like a very-demanding judge at a powerlifting meet, those that have been a little lax in training will have a rude awakening. It’s not the judge’s fault; it’s the athlete not knowing the rules or definitions of what is counted and what is not allowed. If you prefer to coast through the stop sign, you will probably struggle with our system.

Why so much discussion of what a rep means, you may ask. In short, the answer is that coaches that demand quality, research-grade data have to do their part in the data collection process. Strict technique based on the common definition of the movement must be adhered to or it’s technically a different exercise and the sensor may not pick up the repetition. Research that tests athletes with simple exercises or with Smith machines may have good intentions, but when the rubber hits the road in the weight room, much of the validity is lost.

I have been a staunch advocate for creating measurements “in the wild,” or in collaboration with athletes who are training properly, not from machine learning or similar. I would rather have calculations based on valid movements versus allowing too much slack, and thus delivering inaccurate data. In this scenario, what’s the point?

The military work we do is the inspiration for what I call “Barbell Discipline,” or the ability to follow instructions time after time. Last year, I had a product training meeting with a Special Ops Division head performance coach. We talked about the system movement requirements, and he said “no problem, my guys follow instructions.” Strict execution while allowing for natural style is necessary for testing reliability. Unfortunately, coaches sometimes don’t like strict procedures, but a bodyweight squat jump test with a small countermovement is not a squat jump test. The point of the test is to see what you can do without any stretch reflex.

If you have the proper squat jump assessment and the countermovement jump assessment, then you can properly look at eccentric utilization ratio (EUR), which is a powerful metric to consider. Coaches demand accuracy and validity from the devices, but the engineers need the same from movements protocols being conducted in the field. How many times do we allow athletes to cheat or get away with compliance of a protocol just to get a number? Strength coaches promote discipline and obedience because it sounds nice to the head coach, but in order to benefit from that philosophy in the weight room, they need to start with accountability in testing and measuring.

Immediate Feedback, Autoregulation, and Repetition Recovery

The combination of multiple methods of training using barbell data as feedback is a phenomenal opportunity in training. Some examples of the reason we use the rep-by-rep flash and alert sound are to reduce drift error (common with accelerometers) and leverage the athlete’s inter rep recovery period. The amount of time between bouts of effort is part of the equation of cluster sets, or lifting sets that manipulate recovery times between single or low repetition ranges. Our system is not for cranking out reps, which is counterintuitive to the purpose of using VBT methodology.

“Using barbell data as feedback on multiple training methods is a phenomenal opportunity in training.”

During power/speed training, every rep needs to count, with full reset by the athlete and full concentration for each rep. Maximizing effort is emphasized. You would be amazed what the total power output looks like over a five-rep set using our system method versus free forming through the reps. Sure, sometimes you may want the athlete to crank out reps, with a different training goal, so go for it. Keep in mind, just because you have a VBT measuring tool, it does not mean you need to use it all the time. I actually advocate for less assessment time, as there’s no need to create numbers for numbers’ sake. Pick your spots and do it right. Make the days the VBT tool is on the barbell competitive days, not part of a daily routine.

Video 2: My presentation from 2010 when I was with Myotest, the first accelerometer barbell tracking product in the market. What we learned from a decade ago is now being put to use, as coaches are learning more about best practices with cluster training and potentiation.

With all the science and support by coaches, you would think cluster sets would be a trend and popular request with us, but they’re not. Obviously, the logistical factors of sharing a rack with other athletes is one thing, but we have not encountered as many coaches performing autoregulation and cluster-style training because managing it with teams is far different than using it for your own training. How hard, how much, and when to stop are the things coaches have a thirst for. Cluster sets are perfect options for teams when athletes can share similar loads, but also great for organized groups as long rest periods can include partnered training if instructed properly.

Autoregulation is great on paper, but it really is nothing more than adjusting on the fly versus what is planned. One of the strongest arguments for VBT is the use of the immediate feedback of data to add or lower the weight based on how the athlete is feeling at that particular time. Combined with a good training plan, autoregulation can be part of warm-up and work sets for a true optimal load.

Just because you have a VBT measuring tool does not mean you need to use it all the time. Share on X

Finally, we get to motivation, which can be a double-edged sword; meaning VBT feedback is great to utilize for higher levels of effort, but it can drive athletes into the ground if they are not supervised properly. Nobody wants to be the bad guy and pull them away from a motivational challenge, but injuries are real. Warning signs must be acknowledged and acted upon.

Are You Willing to Change or Want to Be Comfortable?

I realize some coaches reading this article will likely want to argue the science to continue what they do, and not change what they do or believe. Change can be painful and uncomfortable, but it is necessary to be competitive. Uncomfortable change has been part of our process. If you want better results, you must look at things differently, with a fresh lens.

Ask the tough questions and challenge your own beliefs and preferences in training. We are on the same side—working together to help athletes—and exploring the concepts shared here will move training forward.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

Body composition is often overlooked as an important metric, but it’s crucial to have a detailed understanding of how it applies to performance and health. There is a general misunderstanding of body composition in sport.

First, we’re not only concerned about the type of mass (i.e., percent fat, fat-free mass, fat mass), but also the type and distribution of mass. The distribution of an athlete’s lean and fat mass will influence how they move through space. Two athletes who weigh 250 pounds and have 15% body fat will move very differently if their upper to lower mass ratio is 1.7 (top-heavy) or 1.5 (bottom heavy).

Second, there is no clear definition of what good or ideal body composition is for sport. I’ve spoken with many coaches who have a range for different athletes, but there’s a big difference between a general range and an ideal range. We need to consider ideal body composition in the context of the demands of the athlete’s sport and their body frame.

Finally, there are many ways to measure body composition and each has different levels of accuracy, reliability, and feasibility. Having spent time in both applied and research settings, I understand that we usually have to pick two out of three of these (i.e., accuracy vs. reliability vs. feasibility). Which two you pick determines the cost, another important factor.

For athlete body composition, accuracy and reliability are more important than feasibility, but there is a way to get all three. Body composition does not need to be measured daily, weekly, or even monthly because meaningful changes take time.

DXA: Advantages and Limitations

Two to four measurements a year with dual x-ray absorptiometry (DXA) will benchmark changes and help us understand the type and distribution of mass. DXA scans paired with more feasible measurements like weight, 3D scanning, and in some cases bioelectrical impedance allow us to track changes between scans with more accuracy.

While many consider DXA a gold standard, it’s not without its limitations. First and foremost, DXA uses ionizing radiation. While the absolute dose is minimal for each scan (less than spending eight hours outside on a sunny day), we need to be cautious. That’s why we recommend two to four scans each year.

Other limitations include cost and scan time. Because machines cost $70-$100K and individual scans range from $75-$150, cost is a legitimate issue. But accuracy and reliability are expensive. We can buy a 60-inch flat screen TV for $100 bucks, but if it only lasts a few months, wouldn’t it be better to spend more money for a reliable high-quality TV?

DXA also has a big limitation in the interpretation of the data. Currently the reporting capabilities of DXA are limited to multipage hard copy reports (5-15 pages per athlete) or CSV export with over 200 variables for each athlete. I believe this is a critical reason why there has not been widespread adoption of DXA in sport, and it’s one of the reasons we started Dexalytics. There is a lot of valuable information obtained from a single DXA scan; we wanted to create a solution that pulls this information out and displays it clearly.

Because DXA provides so much information, the critical information sometimes can be missed. In addition to the traditional metrics of %body fat, total lean mass, and total fat mass, DXA provides accurate and reliable segmentation measurements for different regions of the body. It also gives asymmetry measurements of the right and left sides of each region. These data points allow us to calculate functional ratios of an athlete’s mass distribution.

We can also create custom regions of interest (ROI) for specific measurements of other parts of the body.4 For example, we recently published a method to measure the leg’s anterior and posterior compartments.4 We can save and replicate these custom ROIs over time to create additional information that could be important in return-to-play scenarios.

More data is not always better if we can’t interpret it or summarize, analyze, and disseminate it promptly. And it’s critical to understand that body composition is not just about totals, it shows how the different parts contribute to that total.

Bone Density and Athletes

Bone mass and bone density measurements are important for monitoring athlete health. Bone density issues are usually associated with female distance runners. But look at all of the bone stress injuries that are becoming more common in other sports (the NBA, for example). There is a need to start tracking bone density in athletes.

Two important things to remember:

• DXA measures the overall density of the bone (g/cm3). It does not measure the specific structure and strength of cortical (outer) versus trabecular (inner spongy) bone that you may get from peripheral quantitative computed tomography (pQCT) or other methods.
• Bone density needs to be compared in terms of like versus like. When you get a DXA, you typically will get t- and z-scores compared to the normative DXA database for total bone mass density (BMD). In our experiences, the vast majority of athletes will have t- and z-scores above two or three.

T- and z-scores refer to the amount of deviation above and below the mean of the data. Although two or three is well above the age and gender average for the normal population, athletes are not part of the normal population. They need to be compared to similar individuals in their sport and their position.

Some athletes can be at risk even with a high z-score of 2.5 (2.5 standard deviations above the mean) when compared to everyone else who plays their position and they fall in the lowest 10%. We identify the individuals in the lowest 10th percentile for their position and sport, and we pass that information along to their medical staff to decide if further assessments are needed.

Visceral Adipose Tissue

DXA also estimates visceral adipose tissue (VAT). VAT is fat tissue that surrounds our internal organs and is associated with chronic inflammation and several cardiometabolic diseases. The body does not want to store fat in the visceral region. But subcutaneous (above the muscle layer) fat stores are limited, so spillover occurs into the visceral regions and other ectopic depots (for example, the liver and heart).

We’ve demonstrated that VAT in male athletes significantly increases when they’re above 20% body fat. Females store fat better, and we have not observed significant increases in VAT in women until about 40% body fat.

Tracking VAT in athletes with large body types can help maintain their health and well-being. Share on X

This puts some larger athletes at significant risk of increased VAT stores. Especially collegiate and professional offensive and defensive linemen who, on average, have 28-32% body fat. This becomes even more important after retirement when activity levels decrease, adding to a high likelihood of increased body fat accumulation. Tracking VAT in athletes with large body types is important for maintaining their health and well-being.

Bringing the Team Together with Information

Almost every athlete has a large support network to improve or maintain their health and development. While everyone agrees that the athlete is (and should be) at the center of this group, communication among these individuals is sometimes lacking.

Moreover, if we share data without any context, we risk multiple interpretations and communication of varying messages. We focused on this when designing Dexalytics. We want to provide information that is understandable for everyone, so the entire team is on the same page and moving the athlete in the same direction.

We understand that each member of the team will view the data through their unique lens; that’s what makes them specialists in their area. We summarize the data in a way that makes the initial message clear: This is where this athlete is at now, this is the change from their last scan, and these are the areas that can be improved. The additional context and information that comes from each specialist then become even more valuable.

Body Mass: Ratios and Symmetry

We based Dexalytics on over 20 years’ experience with DXA and our belief that meaningful information is missed when we rely on totals. Imagine using only the total load metrics from player tracking devices. Yes, it can be done and does provide some value. But much more information and context are garnered from looking at the type and intensity of movements that contributed to that load.

The type and distribution of load are similar to the type and distribution of body mass. Share on X

The type and distribution of load are similar to the type and distribution of body mass. When we measure body composition, we first look at the traditional metrics. Then we want to know about the ratios and symmetry of the body, and we want to do all this within specific parameters of an athlete’s sport and position.

Body Types and Sport, Player Positions

The information allows us to compare similar body types. Exploring body type is incredibly important in sports because there are dramatic differences between positions (for example, American Football). From there, we look more in depth and begin to identify body composition differentiators that are associated with on-field and on-court sport success.

Bigger is not always better for every athlete; added mass can lead to slower movement, increased load, and greater stress. Without knowing what the body is made of, how can we know what the body is capable of?

We’re very interested in the changes that occur during a competitive season and recently completed postseason scans for a variety of sports teams. We’re finding that change is even more complex than simply mass or percent mass going up or down.

For example, ten athletes had an increase in percent fat mass ranging from 1-4% from the start to the end of the season. Three athletes increased lean mass and fat mass (with a disproportionate increase in fat mass to lean mass). Two lost lean mass and maintained fat mass. Two others lost lean mass and increased fat mass. And two athletes maintained lean mass and gained fat mass while one lost lean mass and fat mass (a higher proportion of lean mass lost).

It’s noteworthy that the converse was also true. Of the group that had lower percent fat at the end of the season, there were multiple variations of how this occurred. Most of us would agree that increases in percent body fat would be expected (although not ideal) over the season. But which of these five different options is better or worse for maintaining performance? Admittedly, I don’t know the answer yet; there’s a lot we do not know about body composition and performance in athletes.

Type and Distribution of Body Mass

To further complicate things, we have to look at where the increases and decreases came from for both fat and lean (muscle) mass. Loss of leg muscle mass is not ideal just as gaining fat mass in the abdominal or gluteal region would not be ideal.

We often see lean mass increases in the trunk with similar losses in the legs, which would register as no change in total lean mass or FFM (depending on your method). In one extreme case, we retrospectively observed an athlete gain 16 pounds of muscle in his torso and lose 16 pounds in his legs.

These shifts go unnoticed when we look only at totals, but they are far more important than the change in the total mass. To account for these changes, we’ve created the AthleteDex—a composite score of total and regional mass measurements that factors in changes in functional mass.

Functional mass refers to the type and distribution of mass that is changing. For example, an athlete who maintains their total mass with a loss in leg lean (muscle) mass is classified as a functional loss. In most sports, the legs are the primary mover and losses in the legs are associated with decreased strength and power.

We also produce an index of lean and fat mass to describe the relative change in these to compartments.

The Future of Body Composition

Body composition is an undervalued metric in sports, mostly due to a misunderstanding about what body composition is and a reliance on feasibility over accuracy. Nevertheless, as the quest for more and better data continues to increase in elite sport, I foresee a greater interest in athletes’ bodies beyond totals (and yes I am clearly biased in this regard).

Several Division 1 programs, multiple Olympic training centers, and double-digit professional sports franchises currently use DXA with their athletes, with a DXA on site or through a third party.

As a researcher, I want to move beyond traditional total metrics and start using metrics that describe not just the type of mass but the distribution of that mass.

We recently began a 10-year study to measure 4,000 athletes from high school through retirement (longitudinal and cross-sectional) to understand how athletes evolve over different periods of their careers. As our database continues to grow, we’ll get even better at identifying the frame size for different athlete body types. A clear understanding of how much mass each frame can hold will help inform changes in body composition over time.

At Dexalytics, our mission is to create better information, allowing for better decisions to develop better athletes. You can check us out at our website Dexalytics. If you would like to talk or see a demo of Dexalytics, I can be reached by email at [email protected] or @tylerAbosch on Twitter.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

References

1. Dengel, D. R., T. A. Bosch, T. P. Burruss, K. A. Fielding, B. E. Engel, N. L. Weir, & T. D. Weston. “Body Composition and Bone Mineral Density of National Football League Players.” Journal of Strength & Conditioning Research 28.1 (2014): 1-6. doi:10.1519/JSC.0000000000000299.
2. Bosch, T. A., T. P. Burruss, N. L. Weir, K. A. Fielding, B. E. Engel, T. D. Weston, & D. R. Dengel. “Abdominal Body Composition Differences in NFL Football Players.” Journal of Strength & Conditioning Research 28(12) (2014): 3313-3319. doi:10.1519/JSC.0000000000000650.
3. Bosch, T. A., D. R. Dengel, J. R. Ryder, A. S. Kelly, & L. Chow. “Fitness Level is Associated with Sex-Specific Regional Fat Differences in Normal Weight Young Adults.” Journal of Endocrinology and Diabetes 2(2) (2015):5.
4. Raymond, C. J., T. A. Bosch, F. K. Bush, L. S. Chow, & D. R. Dengel. “Accuracy and Reliability of Assessing Lateral Compartmental Leg Composition Using Dual-Energy X-Ray Absorptiometry.” Medicine and Science in Sports and Exercise 49(4) (2017): 833-839. doi: 10.1249/MSS.0000000000001168.
5. Bosch, T. A., A. Carbuhn, P. R. Stanforth, J. M. Oliver, K. A. Keller, & D. R. Dengel. “Body Composition and Bone Mineral Density of Division 1 Collegiate Football Players, a Consortium of College Athlete Research (C-CAR) Study.” Journal of Strength & Conditioning Research 2017 [Epub ahead of print]. doi:10.1519/JSC.0000000000001888.
6. Buehring, B., D. Krueger, J. Libber, B. Heiderscheit, J. Sanfilippo, B. Johnson, I. Haller, & N. Binkley. “Dual-Energy X-Ray Absorptiometry Measured Regional Body Composition Least Significant Change: Effect of Region of Interest and Gender in Athletes.” Journal of Clinical Densitometry 17(1) (2014): 121-128. doi.org/10.1016/j.jocd.2013.02.012.
7. Nana, A., G. J. Slater, W. G. Hopkins, & L. M. Burke. “Effects of Exercise Sessions on DXA Measurements of Body Composition in Active People.” Medicine and Science in Sports and Exercise 45(1) (2013): 178-185. doi:10.1249/MSS.0b013e31826c9cfd.
8. Binkley, T. L., S. W. Daughters, L. A. Weidauer, & M. D. Vukovich. “Changes in Body Composition in Division I Football Players Over a Competitive Season and Recovery in Off-Season.” Journal of Strength & Conditioning Research 29(9) (2015): 2503-2512. doi:10.1519/JSC.0000000000000886.
9. Trexler, E. T., A. E. Smith-Ryan, J. B. Mann, P. A. Ivey, K. R. Hirsch, & M. G. Mock. “Longitudinal Body Composition Changes in NCAA Division I College Football Players.” The Journal of Strength & Conditioning Research 31(1) (2017): 1-8. doi:10.1519/JSC.0000000000001486.

The brain has an extraordinary way of processing and adapting to our environment to make us more skilled in our movements. Research trials heavily study athletes to refine our understanding of the mechanisms of the brain’s plasticity.

In this article, I’ll discuss the neuroscience behind skill development and mastery, learning by mental focus, neurocognition and agility, learning by observation, and the intrinsic and extrinsic effects on learning.

Skillfulness Patterns and Constraints

In Clark’s (1995) On Becoming Skillful: Patterns and Constraints, the author outlines the four main components of dynamic systems: constraints, self-organization, patterns, and stability. Constraints occur in the individual, the environment, or the task, and all three combine to confine the resulting behavior. Under these constraints, an individual must find equilibrium, or stability, through the process of intrinsic self-organization.

A person’s innate characteristics determine their individual constraints. Examples include height, weight, fitness level, motivation, and anxiety.¹² These physical, mental, and emotional attributes are always changing and largely influence an athlete’s adopted playing style.

Overweight, lethargic, unmotivated players, for example, will play much differently than a hard-working, fit, and energetic players. Although the required functional movements are the same, the approach is much different. The fit athlete will play efficiently and conform to the dynamics of the game, whereas the unfit player may lack the ability to react both mentally and physically to game dynamics.

Environmental constraints include the facility, playing surface, surrounding people (athletes, coaches, parents), weather, noise level, and lighting, to name a few.¹² The environmental pressures felt by an athlete can dramatically affect motor skill acquisition and, therefore, gameplay; any discomfort in the environment can inhibit proper learning.

For example, if young athletes feel tremendous parental pressure to perform well in a given sport, they may put too much conscious effort into motor learning development, causing incorrect or inadequate skill acquisition.

Coaching Tips

• Create a relaxed learning process so the brain can develop flexible motor skill patterns to apply across a variety of play scenarios in a dynamic game situation. If an athlete has felt pressured, their patterns are too rigid, and they are too inflexible to adapt dynamically.
• Coaches can manipulate task-specific constraints in several ways, including changing the rules of play, the end goal, or the equipment used to complete the task. Great examples are playing soccer with a smaller or heavier ball, having smaller goals, or limiting the ability to shoot inside the 18-yard box. These scenarios require the athlete to apply previously acquired skills to the new task constraints—call it a dynamic range of motion for both the brain and the body.

The body constantly conforms to new environments, both internal and external, without ever having to consciously process the surplus of information filtered through the senses to the brain.

Each pattern previously generated from a specific skill movement is reinforced by practicing the same movement under the same context. Or it is re-circuited to produce a dynamically similar movement and achieves the same goal.

The dynamic nature of athletics offers a great example of how skillfulness patterns and constraints are accounted for in gameplay and adapted during motor skill development.

Skill Retention

Retaining a skill is probably the most critical component of the learning process. Without retention, the process becomes pointless. Jacoby’s analogy states that the outcome of a particular movement can be achieved by either a conscious process or by simply retrieving a solution from memory.⁹

If the solution is fresh in one’s mind from a previous attempt, the process can be skipped to achieve the same solution. However, if the solution is not fresh, the process will have to take place again, providing a chance for reinforcement.

For progressive overload to occur, we must consistently build problem-solving into the training program. I don’t mean this in the most literal sense of an athlete’s training program, such as the theory of muscle confusion.

For progressive overload to occur, consistently build problem-solving into the training program. Share on X

Rather, it’s a way to provide variability for the brain to process with thought instead of simply retrieving without thought. Cognitive processing reinforces the motor pathway in a permanent manner, but retrieval can easily be forgotten once repetition stops.

Blocked-order practices repeat a movement with the intention of reinforcing the pattern until it becomes part of our muscle memory.⁹ Over time, according to the theory, problem-solving is no longer required to reach the same conclusion we learned initially.

Often highly skilled athletes don’t understand how they do a movement so well; they can’t explain the process. Does this mean they’ve forgotten? Lee, Swanson, and Hall (1991) questioned a person’s ability to construct future action plans under this type of blocked-learning environment.

Random-order practice, in contrast, uses many variations of a skill into learning development. The theory here is that the brain needs to completely regroup and execute a new plan for each trial, forcing a novel learning opportunity.

When blocked- and random-order practices were compared, participants in the random group outperformed the blocked group in retention and transfer of learning.⁹ Contextual-interference provided the cognitive stimulus necessary to exceed the threshold of learning.

The platonic arrangement of blocked practice, after the initial learning curve, does not create enough of a stimulus to approach the learning threshold and is less effective in the long run.

Coaching Tips

• Increasing variability in training is a simple solution that any coach or trainer can make in practice.
• Tweaking an exercise movement slightly between trials can encourage the brain’s problem-solving capacity to remain activated. Reduced cognitive and physical fatigue are other benefits.
• Performing the same style movements may seem specifically productive to athletes and their sports. But the increased risk of overuse injury and lack of skill retention are not worth the specificity. It’s best to mold a well-rounded athlete with solid problem-solving skills and versatility to adapt to many in-game situations.

Learning with Mental Focus

In athletics, there is no doubt that mental skills play a crucial role in the level of performance achieved. Unfocused athletes fail to meet the demands of their sport and often lack the motivation to do so. Focused athletes zone in on the game situation, filter stimuli, and respond efficiently to a game’s dynamics.

Questions arise about where the focus is directed. Does the athlete have an internal focus on consciously controlled body movements, accounting for accurate skill? Or is the focus on the external effects of the unconsciously produced movement?

With internal focus, the athlete concentrates on the specific steps and movement patterns required.¹¹ This tends to constrain the system by placing too much emphasis on minute skill movements rather than the big picture of the game scenario at hand. However, when learning a new skill or correcting a skill error, internal focus is beneficial.¹³

With external focus, the athlete intuitively selects the most efficient motor pattern for completing their task with concern only for the outcome of the move. Some research shows that a novice athlete undergoing motor learning does benefit from internal focus and that learning is inhibited if they become distracted from their task.¹³

The opposite is true for elite athletes with well-learned skills who operate primarily on autopilot in performance situations.

An interesting study by Porter and Sims (2013) examined instructions to focus on internal, cued movements and external environmental cues and the instructions’ effect on sprinting performance. They found that sprint performance in the control group, who received no directions, performed much better than the groups who received internal and external focus cues.

The researchers believed that providing no instructions allowed the athletes to naturally select their most efficient motor and mental pathways to achieve maximum sprint effort.

Coaching Tips

• Coaches should avoid such sprint cues as, “drive your arms hard out of the blocks, keep the heels low, and push the toes forcefully into the ground.” These are internal focus cues which may hinder the athlete’s natural mental efficiency.
• Instead, more general cues such as “be powerful down the track,” or “explode out of the blocks,” may be more effective, allowing the athlete to conform their individual motor skills within the necessary framework.

Neurocognition and Agility in Elite Athletes

The Fitts and Posner three-stage model of motor skill learning progresses from cognitive to associative to autonomous learning levels.¹⁰ The cognitive stage has a steep learning curve where we learn basic movements with a general goal in mind. In the associative stage, also known as the refining stage, fundamental movements are presented and become more functional through practice. Finally, in the autonomous stage, we perform the motor skill on a subconscious level, a sign of complete mastery and expert status.

Increasing automaticity is associated with mastery because below this level, conscious and controlled processes are inefficient and demand attention.¹⁴ An athlete in this stage shows smooth, effortless, and completely efficient movements.

Can automaticity be achieved at lower levels of learning? Automaticity does not always indicate elite status. However, elite status does indicate automaticity. Some athletes fall into the category of automaticity on a mediocre level due to their comfort with their ability and routine. Repetition yields automaticity simply by a force of habit. But without refinement, the athlete’s motor development will stagnate on the subconscious plateau.

Reaction seems automatic, but elite athletes have a refined method of in-play decision-making. Share on X

Although their reaction seems automatic, elite athletes have a refined method of in-play decision-making. The theory is that many possible actions are released in parallel, so a speed advantage exists when choosing the best-odds move, even before receiving all the information in the environment.¹⁴

This is different than the processing system of a novice or intermediate athlete who is still in the cognitive or associative learning stages. The possible actions are consciously brought to the athlete’s attention, assessed individually, and weighed in the decision-making process. The reaction times yielded from the two groups are drastically different.

An amazing concept in neuroscience that’s not yet fully understood is the brain activation that results from visually imagining a particular action or scenario. For example, an elite athlete can quickly envision each possible outcome from directing a soccer ball downfield with numerous passing opportunities. This happens in split-second imagery before the ball is even touched.

A functional MRI of the brain would show intense activation of the motor pathways before the actions are physically carried out. The strongest elicited neural response will become the chosen decision. All of this occurs without the athlete’s voluntary control of the play.
Developing an elite athlete’s automaticity may involve a more refined degree of underlying cognition than scientists currently theorize.

Coaching Tips

• When developing agility training programs, don’t neglect the neurocognitive and neuromuscular connection because it’s a vital training component. For an athlete to progress to the elite level, they must reach and master a degree of subconscious perceptual-cognitive reaction ability.

Observational Learning

Our two main methods for developing skills are through intrinsic and extrinsic learning. Intrinsic development occurs when the learner performs and uses self-analysis to generate feedback from trial to trial. Extrinsic learning requires stimuli in our environment to initiate motor pathway development and follow-up feedback regarding our performance in that environment.

Demonstrations are a good way to teach a new skill. A demonstration requires the learner to extract perceptually relevant information from the environment to draw a generalized motor plan.

A study by Buchanan and Dean (2010) investigated the effect of having many versus one strategic solution(s) to the goal of a task. One group received verbal instruction as well as visual demonstration and performed more quickly and precisely than a group that did not have verbal help. The authors also explained that, if visual or verbal help is not included, exploratory learning hinders motor development.

A study by Hayes, et al. (2007) tested whether demonstrations help children learn a new skill. Children watched a video of a bowling action and were asked to imitate the action. The researchers found that children used the visual information to produce relative motor function, which is theorized to be very important in the early stages of learning coordination. The child’s goal is to produce a simplified version of a demonstration to achieve the same result. Unless children receive guided information or cognitive rehearsal strategies, the researchers suggested that reproduction and consistency will be lacking.

Do demonstrations need to be performed perfectly to be effective? Technical skills have internal representations of a specific movement, so it may seem counterintuitive to demonstrate a flawed version of an ideal movement.

A study by Domuracki, Wong, Olivieri, and Grierson (2015) explored the impact of flawed versus flawless demonstrations for medical trainees in a clinical setting. They concluded that flawed demonstrations provided errors for the improvement of global performance, as long as the trainees knew that they were watching error-ridden movements. The flawed demonstration approach provided feedback of how not to perform a skill.

Both perfect and imperfect demonstrations may be necessary to achieve maximal skill development. Share on X

Demonstrations provide a tremendous way to pick up novel motor skills quickly. In most cases, they allowed for the adoption of a generalized motor plan. Children especially benefit from verbal guidance through the developmental process.

Mixed observations of both perfect and imperfect demonstrations may be the happy medium necessary to achieve maximal skill development.⁵

Coaching Tips

• Any coach can add demonstration to their toolbox. It’s a tool that should be applied based on the athlete’s age and maturity level.

The Neuroscience of Learning

Huang, Hazy, Herd, and O’Reilly (2013) proposed a two-way learning model consisting of a slow-learning parietal pathway and a fast-learning hippocampal pathway. This applies to instructional learning as a stimulus-response (S-R) mechanism. The largest area of involvement in the brain lies in the lateral prefrontal cortex, premotor, and posterior parietal cortices.

The slow-parietal pathway processes simpler, routine mappings while the fast-hippocampal pathway processes new instructions via S-R mapping. Instructional-based learning is easy to follow and easily guided step-wise. Also, learning occurs more quickly than if a new motor pattern attempted to rewrite over an old one (slow pathway).

Observational learning manifests slightly differently. Mirror neurons in the F5 motor area of the prefrontal cortex are directly activated when someone watches a demonstration.¹⁰ Located in the inferior frontal gyrus, this area does not stay activated once the reproduction of the movement begins.

Remarkably, Broca’s area of the brain activates simultaneously, indicating there’s a component of speech to the learning pathway. Researchers are steadily investigating the theory that these mirror neurons exist.

The takeaway point from the Huang study is this—instructions can be memorized easily by the fast-hippocampal and then reproduced via top-down processing from the prefrontal cortex-basal ganglia system.

It would be useful to quantify the speed of mirror neuron development and processing. On another note, it would be interesting to do a parallel study which compares observational and instructional learning side-by-side. The findings would help researchers understand which method of learning causes the brain to adapt more quickly.

Mirror Neurons

As noted, observational learning directly activates unique mirror neurons in the F5 motor area of the prefrontal cortex. The F5 area contains a motor homunculus, or representation of the mouth and hand actions.¹ Mirror neurons possess several distinct features that differentiate them from other neurons in the brain.

First, they’re highly specialized. During observation, mirror neurons only fire when a “biological effector,” or body part that causes a movement, interacts with an object. In other words, a hand will not fire a mirror neuron while resting. The same is true for visualizing the object involved when it is out of context.

A mirror neuron also does not activate when one mimics a particular motion. For example, throwing a ball will activate the mirror neuron while a throwing motion without the ball will not.

Throwing a ball will activate the mirror neuron; a throwing motion without a ball will not. Share on X

Much of the evidence for mirror neurons discredits any genetic predisposition or association. The associative learning theory explains that neural pathways in the brain for mirror neurons develop as a result of environmental stimuli.³ Some theories of observation suggest that psychological state, strategy, intention, or rationalization can influence the development of mirror neurons.

The associative theory, however, is purely based in automaticity. This nurture model fails to account for abilities in infants not observed in their environment, such as hand grasping and object manipulation. Infants reproduce observed facial gestures even though they cannot see their face.⁶ This indicates that some innate, pre-established neuron pathway is responsible for this ability.

This genetic model, however, has limitations as well. If mirror neurons are truly innate evolutionary adaptations, the critical periods of environmental influence on brain plasticity do not fit the mold.

Ferrari, et al. suggested an epigenetic model for the growth and development of motor neurons indicating a stabilizing selection of phenotypic traits based on environmental influence, especially during early childhood development.

This brings the two theories of nature versus nurture together into one all-encompassing model.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

References

1. Buccino, G. & Riggio, L. (2006). “The Role of the Mirror Neuron System in Motor Learning.” Kinesiology, 38(1), 5-15.
2. Buchanan, J. J., & Dean, N. J. (2010). “Specificity in Practice Benefits Learning in Novice Models and Variability in Demonstration Benefits Observational Practice.” Psychological Research, 74(3), 313-326. doi:10.1007/s00426-009-0254.
3. Catmur, C., Walsh, V., & Heyes, C. (2009). “Associative Sequence Learning: The Role of Experience in the Development of Imitation and the Mirror System.” Philosophical Transactions of the Society B, 364(1528), 2369-2380. doi:10.1098/rstb.2009.0048.
4. Clark, J. E. (1995). “On becoming skillful: Patterns and constraints.” Research Quarterly for Exercise and Sport, 66(3), 173-183.
5. Domuracki, K., Wong, A., Olivieri, L.,& Grierson, L. E. (2015). “The impacts of observing flawed and flawless demonstrations on clinical skill learning.” Medical Education, 49(2), 186-192. doi:10.1111/medu.12631.
6. Ferrari, P. F., Tramacere, A., Simpson, E. A., & Iriki, A. (2013). “Mirror neurons through the lens of epigenetics.” Trends in Cognitive Science, 17(9), 450-457. doi:10.1016/j.tics.2013.07.003.
7. Hayes, S. J., Hodges, N. J., Scott, M. A., Horn, R. R., & Williams, A. M. (2007). “The efficacy of demonstrations in teaching children an unfamiliar movement skill: The effects of object-oriented actions and point-light demonstrations.” Journal of Sports Sciences, 25(5), 559-575. doi:10.1080/02640410600947074.
8. Huang, T., Hazy, T. E., Herd, S. A., & O’Reilly, R. C. (2013). “Assembling Old Tricks for New Tasks: A Neural Model of Instructional Learning and Control.” Journal of Cognitive Neuroscience, 25(6), 843-851. doi:10.1162/jocn_a_00365.
9. Lee, T. D., Swanson, L. R., & Hall, A. L. (1991). “What is Repeated in a Repetition? Effects of Practice Conditions on Motor Skill Acquisition.” Physical Therapy, 71(2), 150-156.
10. Magill, R., & Anderson, D. (2013). Motor Learning and Control: Concepts and Applications (10th ed.). New York: McGraw-Hill.
11. Porter, J. M. & Sims, B. (2013). “Altering Focus of Attention Influences Elite Athletes Sprinting Performance.” International Journal of Coaching Science, 7(2), 41-51.
12. Renshaw, I., Chow, J. Y., Davids, K., & Hammond, J. (2010). “A constraints-led perspective to understanding skill acquisition and game play: A basis for integration of motor learning theory and physical education praxis?” Physical Education and Sport Pedagogy, 15(2), 117-137. doi.org/10.1080/17408980902791586.
13. Tedesqui, R. A. B. & Glynn, B. A. (2013). “‘Focus on what?’: Applying Research Findings on Attentional Focus for Elite-Level Soccer Coaching.” Journal of Sport Psychology in Action, 4(2), 122-132. doi.org/10.1080/21520704.2013.785453.
14. Yarrow, K., Brown, P., & Krakauer, J. W. (2009). “Inside the brain of an elite athlete: The neural processes that support high achievement in sports.” Nature Reviews Neuroscience, 10, 585-596. doi:10.1038/nrn2672.

 

Two years ago, I wrote an article for Freelap on whether antioxidant supplementation was a good idea for athletes. I presented information that illustrated how long-term supplementation with high doses of antioxidants likely has a negative effect on training outcomes, reducing exercise-induced adaptations, and potentially negatively impacting recovery speed. My conclusion was that, on the whole, athletes should probably avoid antioxidant supplementation during training phases.

A few weeks ago, I was at a high-level sports club, discussing with them changes they could make in their training. One of the things I was asked about was antioxidant supplementation, and my advice was that, generally, it was best to stay clear from both a health and performance perspective. As I left that meeting, I felt a bit uneasy. I hadn’t presented the information with all the correct context and, perhaps more worryingly, I was incredibly sure that I was correct. I decided a few years ago that whenever I’m sure I’m correct, I need to revisit the research to ensure that biases haven’t crept in. This article is the result of me revisiting this information, and it therefore acts as an update to my article from 2015.

What Are Antioxidants?

When we exercise, we produce reactive oxygen species (ROS)—often referred to as free radicals—as a consequence of metabolism within the mitochondria, and also muscle contraction. These ROS are highly reactive, so they can damage structures they come into contact with, such as the walls of our cells, and also interfere with normal cellular function. This, in turn, contributes to fatigue, immune dysfunction, and muscle damage, all of which are harmful to sports performance. Antioxidants help to buffer these ROS, reducing the damage they can cause and mitigating the increases seen in fatigue and immune dysfunction after exercise.

There are two main types of antioxidants: endogenous and exogenous. The endogenous antioxidants are produced by our body, which has evolved over the years a very competent system to mitigate oxidative stress. Exogenous antioxidants come from the diet. They include, but aren’t limited to: vitamins A, C and E; selenium; and two classes of nutrients known as polyphenols and flavonoids. Exogenous antioxidants can come from food sources, or from dietary supplements.

A ‘Health First’ Approach

Having discussed what antioxidants are, let’s take a look at whether supplementation with antioxidants is a good idea. To begin with, I’ll approach this from a health perspective: Although it’s easy to forget, athletes are also people, and their lives will last far longer (hopefully) than their sporting career. To that end, it’s important (in my opinion), to take a “health first” perspective. An unhealthy athlete won’t perform to their potential, and an unhealthy athlete might have 70 years after the end of their career for their health to further suffer. My first question, then, is: Do antioxidant supplements improve our health?

To answer this question, I will mostly look at meta-analyses and review articles. Meta-analyses combine the data from a number of studies, and so give a good idea of the overall research in a particular area. The first meta-analysis I want to introduce comes from 2007, and is comprised of 232,606 subjects, which is a lot of participants. The aim of the study was to see whether antioxidant supplements had any effect on mortality. Overall, the results indicated that these supplements had no effect on mortality—i.e., they were neither positive nor negative. Further analysis of the trials allowed the researchers to separate those at low risk of bias. In doing so, the data indicated that beta carotene, vitamin A, and vitamin E, either together or individually, increased the risk of death. Vitamin C had no significant effect.

An earlier study looking specifically at gastro-intestinal cancers found that antioxidant supplementation did not prevent these cancers, but instead appeared to increase their incidence. A 2005 paper found that high-dose vitamin E supplementation might increase risk of death from all causes, and should be avoided. This more or less replicated the results from a 2003 meta-analysis. Another meta-analysis found no effect of antioxidant supplementation on cancer incidence, unless you were a smoker—in which case beta-carotene supplementation increased your cancer risk.

So antioxidant supplementation appears to be at best neutral, and quite possibly negative in regards to health. However, it is also well-established that low levels of antioxidants within the blood are associated with increased risks of death. For example, an older study from 1991 conducted on almost 3,000 men in Switzerland found that overall cancer mortality was associated with lower plasma levels of carotenes and vitamin C, such that being in the lowest quartile for antioxidant intake could increase disease risk by almost a factor of three. Higher plasma levels of lycopene, an antioxidant found in tomatoes, are associated with a decreased risk of prostate cancer.

This is curious; we clearly need antioxidants within our bloodstream to keep us healthy, but antioxidant supplementation appears to be unhealthy, or at best neutral. Why is this? Well, as with most things, the dose makes the poison. Antioxidant supplements tend to contain doses of antioxidants far higher than what would naturally be found. For example, in one of the vitamin E studies above, it was high-dose vitamin E supplementation that was unhealthy. The dose in this case was 400IU of vitamin E, which is the equivalent of around 1kg of almonds or spinach—I’m guessing you don’t eat that much in one sitting, or even in one day.

Supra-physiological doses of antioxidants, in the form of supplements, appear to be at best neutral in terms of health. However, antioxidants from natural sources appear to be healthful, in part because the doses are kept low. In addition to this, antioxidants from food often come with complementary nutrients, which can synergistically work to improve health. High-dose antioxidant supplements often come with few additional nutrients, which in turn can increase the amount of ROS present in the body, causing further damage—as illustrated by the potential increase in mortality seen in the high-dose antioxidant supplementation trials. This is further evidenced by the protective effect of higher intakes of vegetables and fruits (foods that contain the greatest amount of antioxidants) on both cancer and all-cause mortality risk. (Studies one, two, three, four, five, six, and seven.)

Supra-physiological doses of antioxidants, in the form of supplements, appear to be at best neutral in terms of health. However, antioxidants from natural sources appear to be healthful, in part because the doses are kept low.

Bringing this section to a close, we can conclude the following:

• Antioxidant supplementation, particularly at high doses, appears to be at best neutral, and at worst negative for health.
• High vegetable and fruit intake appears to be at worst neutral, and very likely beneficial for health.
• Therefore, it seems appropriate to recommend that, for most people, antioxidant supplementation should be avoided, and higher intakes of fruits and vegetables should be recommended.

Most people should avoid antioxidant supplementation and eat more fruit and vegetables. Share on X

Do Athletes Need a Greater Intake of Antioxidants?

Having looked at general health, the next step is to examine antioxidant requirements of athletes, who are engaged in regular physical activity. It would be tempting to assume that, because exercise increases the amount of oxidative stress, athletes require a greater amount of antioxidants to buffer this. But is that correct?

The evidence tends to suggest that exercise, both through skeletal muscle contraction and also cellular respiration, does increase the amount of ROS that form. Whether this is positive or negative isn’t all that clear. If the body cannot buffer these ROS, they will cause damage, and the more prolonged or intense the exercise, the greater the damage that occurs. However, ROS also serve as important signals for adaptation. They signal for an increase in gene expression, for example, and mediate many of the adaptations following exercise, particularly those that occur within the mitochondria. Exercise itself, and the ROS that form during it, also increase the capacity of antioxidant enzymes, such that individuals who are engaged in regular exercise are better at dealing with oxidative stress than sedentary individuals.

We can consider that, while exercise promotes oxidative stress, this oxidative stress is crucial for adaptation, and one of the adaptations that occurs following exercise is a greater ability to buffer oxidative stress. It’s not entirely clear, therefore, whether athletes do need an increased amount of antioxidants in order to support exercise training. It does appear logical, given that exercise increases oxidative stress, that a greater intake of antioxidant nutrients would support exercise recovery. Indeed, that’s what a number of different papers have found, such as this one.

So Athletes Should Take Antioxidant Supplements, Right?

This is where things start to get interesting. Remember that I previously mentioned that oxidative stress is an important stimulator of exercise adaptations. Well, it follows that when taking in high doses of antioxidants, these signals will be blunted. This is why a number of research papers find that high-dose antioxidant supplementation decreases exercise-induced adaptations.

For example, one study showed that 1g per day of vitamin C (the equivalent of around 14 oranges), reduced some of the beneficial effects of aerobic training. High-dose vitamin C and E supplementation has also been shown to reduce the health benefits of exercise. It’s worth pointing out that this isn’t always what is found; for example this study found that antioxidant supplementation altered muscle signalling pathways after training, but had no effect on actual exercise performance. Note, however, that antioxidant supplementation did not improve training adaptations, again indicating that it is perhaps, at best, neutral.

The two biggest review articles on the subject shed some further light on the evidence. The first of these, published in 2011, concludes that the consistent research finding is that antioxidant supplementation reduces exercise-induced oxidative stress, but that high-dose supplementation blunts exercise-induced adaptations. A second review, from 2014, adds further context. Here, the authors examined 12 studies published between 2006 and 2013. Of these 12, seven reported no effect (positive or negative) on exercise adaptation. Two reported that antioxidant supplementation reduced exercise adaptation, with two showing the opposite—that antioxidant supplementation improved exercise adaptation. The last study only contained partial results.

The interesting aspect from this second review article was the different dosages between the trials. When antioxidant supplementation occurred at high doses (e.g., 1000mg vitamin C, 400IU vitamin E), exercise adaptation was more likely to be reduced. When it was at low doses (e.g., 200mg of vitamin C and 30mg vitamin E), it was more likely to support exercise adaptations. The key thing here, for me, is that these low dosages are easily achievable from food. For example, 200mg vitamin C is around 100g of sweet pepper and 100g of broccoli.

Based on the findings of these research papers, and others like them, we can conclude that:

• High-dose antioxidant supplementation is at best neutral, and potentially negative, when it comes to training induced adaptations.
• Low doses of antioxidants, such as those found in food, appear to have a potentially positive, and at worst neutral, effect on training induced adaptations.
• Therefore, it seems appropriate to recommend that athletes consume the vast majority of their antioxidants from food, which will protect against high-dose intakes of isolated antioxidants.

The Importance of Context

And that was more or less where I left my previous article on this subject—stating that high-dose antioxidant supplementation probably wasn’t a good idea for athletes during training. Based on what I’ve written about so far, I could reasonably conclude that high-dose antioxidant supplementation probably isn’t a good idea for any healthy individual. However, that ignores the context of that person. While chronic antioxidant supplementation potentially reduces exercise adaptation, sometimes in sport we’re not looking to adapt to exercise. For example, in competition, the only goal is performance, not adaptation. And research tends to indicate that, in a competitive setting, antioxidant supplementation likely does have a beneficial effect on performance.

To demonstrate this, a review article from 2015 found that supplementation with antioxidants such as vitamin E, quercetin, resveratrol, beetroot juice, polyphenols, and n-acetyl-cysteine all potentially have performance-enhancing effects on endurance exercise performance. A second review from 2017 found that polyphenol supplements, especially quercetin, could improve performance by almost 3% when taken for seven days before competition, which is far from trivial. This all makes sense: Exercise does increase ROS, and they can cause damage that can reduce exercise performance. While this damage is useful in terms of exercise adaptation, it is a negative if it reduces exercise performance acutely.

This nicely demonstrates the importance of context. When looking to adapt, antioxidant supplements are likely unnecessary, but when looking to compete—when absolute performance is important—antioxidant supplementation may have a role to play. When taken for short periods of time, it seems unlikely that these supplements will have a negative effect on health.

While chronic antioxidant supplementation potentially reduces exercise adaptation, sometimes in sport we’re not looking to adapt to exercise. For example, in competition, the only goal is performance, not adaptation.

During my athletic career, there were other occasions when I was directed to supplement with antioxidants. One was before the Beijing Olympics in 2008, when the medical team was concerned that the high levels of atmospheric pollutants and smog might cause us negative health consequences. Research does tend to suggest that acute antioxidant supplementation might protect against environmental pollutants, and given the pre-competition timing and short duration of supplementation, this might be a beneficial practice.

Other occasions were during high risk periods of immune-suppression, such as post-competition, or during air travel (the two often come together). Here, the research is perhaps a bit less clear: A recent consensus statement seems to indicate that antioxidant supplements have no effect on immune function, and this is supported by research in non-athletic populations. However, being pragmatic, there once again appear to be no negative side effects to this if it occurs infrequently and for a short time period.

Another situation in which there might be a role to play for antioxidant supplementation is when an athlete is restricting food in an attempt to lose weight, as they may be unable to consume sufficient nutrients from the foods they are eating. The same is true when athletes travel outside their normal environment, where nutrient-dense foods may be scarce.

Conclusion

We’ve examined research looking at the effects of chronic antioxidant supplementation on health and exercise adaptations, where the conclusion appears to be that these supplements are at best neutral, and potentially negative. We’ve also looked at acute supplementation of antioxidants, and we’ve seen that there is a potentially beneficial effect of these supplements on performance. There are also a few special cases, such as travel, where there might be a role to play for these supplements.

While the nutrient class of antioxidants has an important role to play in health, it is not a case of more is better. It appears that the doses found naturally within a diet high in fruits and vegetables are sufficient for most athletes, most of the time. Athletes should focus on consuming a wide range of fruits and vegetables of many different colors. These foods often contain complementary nutrients that work synergistically to improve health and performance, and don’t occur at doses high enough to cause issues. By following a diet high in the food sources of these nutrients, along with targeted periods of antioxidant supplementation, athletes can enhance both training adaptation and performance, without sacrificing health.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

 

Accommodated resistance is growing in popularity with both individual and team-based sports. In the weight room, it helps develop power. On the field, it improves sprint power and acceleration mechanics. And in the pool, resisted swim training improves swim sprint performance and muscular strength.

Training with accommodated resistance, such as elastic bands, theoretically gives athletes greater mechanical advantage to assist in the eccentric phase of an activity, applying maximal stored energy into the concentric explosive movement.⁶ Due to the nature of elasticity, resistance increases through a movement’s concentric phase, and this increases muscle activation.⁶6Power and Strength Development

Traditional power development methods involve training for speed and strength independent of each other. New age methods are emerging to produce an augmented training effect for peak power and strength development. One of these methods uses accommodated resistance. Explosive movements, such as those required in many sports, require an extremely quick rate of force development to perform with peak power, a combination of peak speed and strength.⁶

Rhea et al. (2009)⁶ compared the effect of heavy, slow movements to the effect of lighter, fast movements (Slow group) and compared fast movements with accommodated resistance (FACC) to determine the effects of each on peak power and strength development. The only variable that differed between the three test groups of Division I college athletes was the speed at which they performed a squat movement.

Strength improvements were comparable between the Slow and FACC groups. The FACC group, however, experienced a much greater training effect with power development: 17.8% versus 11% in the Fast group and 4.8% in the Slow group.

The theory behind using accommodated resistance in power training clearly has merit. The authors recommended that, as the strength of the athlete increases, the band tension must also increase. For maximal benefit, use a weight that allows the athlete to accelerate through the movement’s full range of motion.

Speed Development

Speed is a function of the optimal combination of stride frequency and stride length, which are considered antagonistic factors.⁵ Stride frequency depends on nerve conduction velocity and, therefore, is largely associated with a genetic ceiling.⁵ Because of this, adaptations to stride length are studied more frequently.⁵

In sprint training, accommodated resistance is often used to develop stride length. The athlete sprints while pulling an external load such as a sled or parachute.⁵ This type of training increases the power and strength of the leg’s extensor muscles by creating an overload stimulus to recruit additional fast-twitch muscle fibers.⁴

For athletes who aim to improve their sprint acceleration for specific sports, resisted sprint training is a valid method to develop strength within a training cycle. Sprinting while pulling an external load recruits additional fast-twitch motor units, improving sprint power and acceleration mechanics.¹

Literature suggests that adding an amount of load which slows an athlete’s velocity by at least 10%, compared to unloaded sprinting, alters their sprinting mechanics.¹ Pulling this amount of load should be avoided at all cost; the loss of proper mechanics can cause the athlete to develop improper neuromuscular movement patterns and less efficient sprint mechanics.

A study by Bachero-Mena and Gonza´lez-Badillo (2014)¹ aimed to discover the optimal training load to improve sprint acceleration. Researchers tested three different external loads with 19 physically active males: 5, 12.5, and 20% of each person’s body mass (BM). After a 7-week resisted sprint training period, with two sessions per week, all three groups improved in 40m sprint time.

The heavy load group (20% BM) significantly improved their 0-20m and 0-30m sprint times. The light load (5% BM) and moderate load (12.5% BM) groups improved significantly in the flying phase but not in acceleration (Light: 10-40m and 20-40m; Moderate: 20-30m and 20-40m). Since the heavy load group trained at slower speeds, their flying phase intervals did not differ significantly from the initial baseline testing.

Resisted sprint training with various loads may improve an athlete’s specific weaknesses in their sprint, whether in the acceleration or the flying velocity phase. Depending on what an individual athlete needs to work on at various points in a training cycle, the appropriate load can be applied for maximal training enhancement.

Resisted sprints may improve an athlete’s weaknesses in acceleration and flying velocity. Share on X

Developing acceleration calls for heavy loads near 20% of an athlete’s BM. Lighter loads from 5-12.5% of BM will improve flying velocity. It’s important to note that the study did not examine unloaded training compared to loaded training. Further research may examine the aggregate effect of both methods.

Makaruk et al. (2013)⁵ examined untrained, physically active female college students as they underwent either resisted (RTG) or standard sprint (STG) training. Researchers measured speed, flight time, ground contact time, stride length, stride frequency, and knee angle in a 20m sprint test. The RTG increased velocity due to increased stride length (slower ground contact time) while the STG exhibited a statistically similar increase in running velocity due to increased stride frequency related to decreased ground contact time.

In my opinion, the tradeoff between ground contact time and stride length is debatable. An increase in stride length also means an increased knee angle at foot strike which places additional stress on the hamstring group and increases the risk of injury.⁵ Increasing the knee angle for force production is also not optimal even though a degree of increased ground contact time allows for more force application. Lately, research has been leaning toward the benefits of improving ground contact time over any other kinematic factor in the running stride.

Another study by Luteberget et al. (2015) ⁴ performed a similar experiment on acceleration development in elite female handball players. In this 10-week study, only traditional sprint training improved 10m sprint time, while both resisted and traditional methods improved 30m sprint time.

Interestingly, this study also examined the training effects on muscle pennation and the lengthening of muscle fibers in response to the training stimuli of both groups. At any relative velocity, longer muscle fibers exerted more force than shorter fibers of the same thickness for sprint performance due to a larger power output of the knee extensor muscles.⁴

Swim Training

The use of resistance and assistance for speed development in ground running sports is common but less so in a non-impact sport such as swimming. Much like running speed is determined by the product of stride length and stride frequency, swim velocity is a function of stroke length and stroke rate.² The terms overstrength and overspeed are often used when referring to resisted and assisted sprint training, respectively.² Both high-resistance and high-velocity training are used to create positive development of power and movement speed through nervous system adaptations.²

A study by Girold et al. (2006) ² compared overstrength and overspeed training in improvements in 100m sprint performance. In both groups, an elastic cord was attached to a swimmer to provide guided assistance ahead of the swimmer or resistance from behind. In the overstrength (resisted) group, the stroke rate, elbow extensor strength, and swim velocity improved, while stroke rate remained unchanged.

In the overspeed group, stroke rate increased, stroke length decreased, and swim velocity remained unchanged. Also, physical strength and the technical parameters directly correlated to swim velocity prediction. In this study, resisted swim training for three weeks improved sprint performance and muscular strength more than the assisted training.

Resisted swim training improved swim sprint performance and muscular strength. Share on X

Another 12-week study examined the effect of dry-land strength training versus resisted and assisted sprint training.³ Researchers found that stroke rate improved in the resisted sprint group. For the 50m sprint, however, there were no significant differences in swim velocity among any of the training groups, although they all improved.

The volume of training was greater in the previously mentioned study (ten versus six sessions per week), which may be why the researchers found no performance enhancement. The practical application of these findings is to incorporate a combined high-volume, high-resistance sprint regimen for the best improvements in swim strength and technical parameters.³

It appears we need more research into accommodated resistance for speed development on land. I’m not convinced that the sprint mechanics retain the same quality or specificity while pulling an external load, though the overload stimulus seems favorable for power development of swim speed. With its growing popularity, we can expect more research on accommodated resistance training in the coming decade.

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References

1. Bachero-Mena, B. & Gonza´lez-Badillo, J. J. (2014). “Effects of Resisted Sprint Training on Acceleration with Three Different Loads Accounting for 5, 12.5, and 20% of Body Mass.” Journal of Strength and Conditioning Research, 28(10), 2954–2960. doi:10.1519/JSC.0000000000000492.
2. Girold, S., Calmels, P., Maurin, D., Milhau, N., & Chatard, J. (2006). “Assisted and Resisted Sprint Training in Swimming.” Journal of Strength and Conditioning Research, 20(3), 547-554.
3. Girold, S., Maurin, D., Dugue, B., Chatard, J., & Millet, G. (2007). “Effects of Dry-Land vs. Resisted- and Assisted-Sprint Exercises on Swimming Sprint Performances.” Journal of Strength and Conditioning Research, 21(2), 599-605.
4. Luteberget, L. S., Raastad, T., Seynnes, O., & Spencer, M. (2015). “Effect of Traditional and Resisted Sprint Training in Highly Trained Female Team Handball Players.” International Journal of Sports Physiology and Performance, 10(5), 642-647. doi:10.1123/ijspp.2014-0276.
5. Makaruk, B., Sozanski, H., Makaruk, H., & Sacewicz, T. (2013). “The Effects of Resisted Sprint Training on Speed Performance in Women.” Human Movement, 14(2), 116-122. doi: 10.2478/humo-2013-0013.
6. Rhea, M. R., Kenn, J. G., & Dermody, B. M. (2009). “Alterations in Speed of Squat Movement and the Use of Accommodated Resistance Among College Athletes Training for Power.” Journal of Strength and Conditioning Research, 23(9), 2645-2650. doi: 10.1519/JSC.0b013e3181b3e1b6.