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The ancient symbol “yin-yang” is said to express the Chinese philosophical concept that describes how apparently opposite or contrary forces may actually be complementary, interconnected, and interdependent in the natural world. This connection perfectly describes the relationship between the concentric and eccentric muscle actions. Lengthening versus shortening, force creating versus force absorbing, and energy dependent versus fatigue resistant: all demonstrate the literal tension between two apparently conflicting but interrelated processes.

In the battle for recognition, however, the concentric activity of muscle is the clear winner. Concentric muscle action gets the credit for virtually everything we do in the world, while eccentric activity toils in the background, working tirelessly but completely unnoticed. We always speak about lifting weights, with little emphasis on how we lower them back down.

Eccentric activity toils in the background, working tirelessly but completely unnoticed. We always speak about LIFTING weights, with little emphasis on how we lower them back down. Share on X

There are now new technologies available that provide resistance for the eccentric movement. This article will discuss the principles of applying resistance during the eccentric lowering phase with emphasis on supplying this resistance safely and effectively.

Muscle Contraction

The best way to fully differentiate between these two distinct muscle functions is to examine them when they are under conditions of maximal stimulation. In other words, expose them to different degrees of loading and then maximally stimulate them to contract. This is exactly what is done when physiologists create the load-velocity curve to describe muscle activity.

Basically, the testing apparatus should isolate the joint that the muscle acts through and begin in the mid-range position. At about half of its full length, maximally stimulate the muscle (in the laboratory by stimulating the involved nerve). With no load, the muscle will contract almost violently at a high velocity. A curve is constructed by repeating the maximal stimulation by incrementally increasing the weights applied to the involved limb. Very predictably, as the weights are gradually increased, the speed at which the muscle shortens begins to decrease.

The curve of these successive trials typically describes a classic parabolic form. Eventually, a point is reached where the weight equals the contraction force of the muscle. Finally, there is some threshold at which the muscle cannot move the weight at all, which is approximately the one repetition maximum (1RM). Up to this point, the relationship between the weights and the muscle force has been very dynamic, with significant differences as the weights were increased.

The Myth of Lengthening

As the weights being applied to muscle in mid-range are increased further, conditions change markedly. When the applied weights actually exceed the force-producing capacity of the muscle, the muscle is then forced to lengthen. This lengthening is radically different from the shortening that occurs with the lighter weights. At just 10% above the 1RM, the velocity of lengthening is barely perceptible. At 20%, 30%, 40%, or even 50% of added weight above the 1RM, the muscle yields very little and lengthens very slowly. When the applied weights get relatively extreme, at 70%, 80%, and 90% above the maximum, the muscle basically gives way, and the velocities increase at a logarithmic pace.

This behavior suggests that the muscle is trying to resist lengthening under these conditions. Everything points to the conclusion that the maximally stimulated muscle under conditions of significant overload tries not to lengthen; in fact, the reality is that muscles cannot themselves lengthen. Every muscle, when stimulated, responds by shortening—and when not stimulated, simply remains unchanged. Only by applying an external tension to pull the two ends of the muscle apart does the muscle lengthen. Muscles cannot lengthen—they can only be lengthened.

Everything points to the conclusion that maximally stimulated muscles under conditions of significant overload try NOT to lengthen. Muscles cannot lengthen—they can only BE lengthened. Share on X

When you look at a combined graph of the concentric shortening and the eccentric lengthening, it is striking how dissimilar the two curves are from one another. On the one hand, the parabolic concentric curve demonstrates the dynamism of the shortening action, while the barely mobile eccentric graph almost appears static.

Static Behavior

The extremely small amount of lengthening caused by ever-increasing amounts of overload suggests that the function of the eccentric muscle activity is, indeed, not to lengthen the muscle but rather to keep it from lengthening under the applied load. In terms of the involved movement, as in the biceps for example, it is more accurate to say that the eccentrically loaded biceps is no longer flexing the elbow, but rather keeping the elbow from extending.

There is, in fact, one other curve that bears a striking resemblance to the eccentric curve: the “stress-strain” curve used routinely in material science.

The stress-strain curve describes the bending of a solid material such as wood, plastic, or metal when it is subjected to a gradually increasing force or stress. There is some minimal level of load applied that causes an unavoidable bending or deformation (strain) of material being studied. It appears that all materials, to different degrees, behave very similarly to a bending force.

Initially, materials bend just slightly, and then as the external force increases, they bend more. Under lighter loads of applied force, the material will return to its original shape when the force is removed. This phase of force application is called “the elastic range.” There, however, begins a level of loading that can actually disrupt the molecular integrity of the material so that when the bending force is removed, the material is permanently deformed. This type of material change is call “plastic deformation,” and aptly, this range of force application is called the “plastic range.” Further loading beyond the “plastic range” is catastrophic and causes macro-damage and material failure, called the “failure zone.”

The importance of comparing the stress-strain curve to the eccentric force-velocity curve is that it implies a therapeutic range for applying overload resistance. The “minimum effective dose” of overload begins at the 1RM for that muscle. You can then apply higher levels of resistance, sometimes as high as 60% or 70% above the 1RM, and although temporary deformation will occur, no structural muscular damage will happen. There is, however, some level where tissue damage and potential harm will occur. This should, of course, be avoided if at all possible.

The importance of comparing the stress-strain curve to the eccentric force-velocity curve is that it implies a therapeutic range for applying overload resistance. Share on X

In this activated, eccentric condition, the muscle behaves like a stiff, passive spring that will initially absorb an outside force by elastic lengthening. The elastic property allows muscle to stretch under a certain amount of overload resistance, absorb the energy, and then release the energy and return to its resting length. Beyond these levels of resistance, there is potential damage to the muscular tissue.

The Molecular Basis of Muscle Function

In order to appreciate how these observations of muscular behavior relate to the actual muscle itself, the molecular basis of concentric and eccentric function needs to be understood.

These two contrasting functions of the same muscle have similarly contrasting molecular mechanics. The classic “Sliding Filament Theory,” developed in the 1950s, has done an adequate job of describing the observed function of muscle during concentric contractions.

The thick filament with its myosin molecules and the thin filament with its actin molecules slide past each other to decrease the length of the sarcomere and hence shorten muscle length. Unfortunately, this model of muscle function had no explanation for the observed properties of enhanced eccentric muscle action. It was not until relatively recently that researchers proposed a new theory that included the eccentric function of the muscle (Nishikawa, 2012). This new theory was called the “Winding Filament Theory.”

There were two major changes to the model that explained the behavior of eccentric muscle action. First, the thick and thin filaments were not described as being simply chains of myosin and actin, respectively. In the Winding Filament theory, the thick filament has as its primary constituent the largest molecule in the human body, titin. Titin extends the full length of the sarcomere and has unique elastic properties. In this model, the myosin molecules are aggregated on the surface of this molecule for their interaction with the actin molecules.

Similarly, the thin filament is not merely a chain of actin molecules. In this case, the core molecule of the thin filament is called nebulin. Although not as marked, nebulin likewise has elastic characteristics, and similarly the actin molecules are situated on the surface of the nebulin molecule for their attachments to the myosin molecules.

Another major difference of the Winding Filament theory, as the name implies, is that the thick and thin filaments do not simply slide past each other. It is here we are reminded that the contractile proteins are helically shaped. This means that instead of simply passing by each other as the sarcomere shortens, they actually wrap around one another and intertwine. While in the shortened state (the beginning of eccentric lengthening), the two molecules are almost indistinguishable as one.

Eccentrics and the Stretch-Shortening Cycle

It is not intuitively obvious how this spring-like molecular quality relates to the function of the whole muscle in the real world. How can the molecule resist the large physical forces encountered in the real world, and how can molecular stretch result in the long ranges of motion required in some overloaded conditions?

The answer is in the arrangement of the titin and nebulin molecules in the muscle itself. First of all, to be able to resist the larger forces, the molecules, like the myofilaments, work together in the cross section of the entire muscle. In cross section, all the molecules work together when force is applied across the muscle. This arrangement of the elastic molecules in cross section is called a parallel arrangement. This is analogous to stretching a rubber band: it is fairly simple to stretch one rubber band, but if you link 10 or 15 rubber bands together in your fingers, stretching them altogether can be difficult. The cross section of the muscle represents the action of many elastic molecules working together.

The question then becomes, how can the stretching of a molecule allow the muscle to extend for the longer lengths seen in actual human function? To explain this, it has to be emphasized that these molecules exist in the sarcomere, and the sarcomeres are connected end-to-end over the length of the muscle in the myofilaments of the myofibers.

Once again, the rubber band analogy can explain the ability to create length. In this case, instead of holding many rubber bands together to increase their resistance to lengthening, imagine forming a chain of rubber bands looped together end-to-end like the sarcomeres—a single rubber band can only be stretched a short distance, but this chain of rubber bands linked together can be stretched for a much longer distance. This looping together of the rubber bands is called “putting them in series.” The behavior of elastic elements working together either in parallel or in series is described in formulas used in Hook’s Law.

What, then, is the function of these spring-like muscles in human function? It is underappreciated that many common human movements expose the muscles to surprisingly high levels of force. Basic walking is just falling forward while standing on one foot and catching ourselves as we land on the other. Although this seems like an extremely low impact activity, each step requires the body to absorb 1.5 times body weight at each heel strike.

It is underappreciated that many common human movements expose the muscles to surprisingly high levels of force. Share on X

The simple act of going down stairs exerts a foot strike that receives 3.5 times body weight of force. In faster activities, the forces go up proportionately. Running, which is basically jumping from one foot to the other, generates an impact force of 2.5 times body weight. To jump, an athlete has to convert their horizontal speed to vertical distance by solidly planting a foot against the ground with a force that can exceed seven times body weight.

The high forces are not just experienced when gravitational forces are encountered but are also present when the muscles must resist the high momentum forces of objects moving at high velocities. Examples of high momentum forces include the acceleration of the low leg during sprinting, the wind-up of the pitcher’s arm, and the back swing of sports equipment such as bats, clubs, and rackets.

Although much has been made about the stretching of the molecules, there is, of course, a time when the molecules “snap back”—i.e., shorten—to their original length. Enhanced force production can occur when the shortening of the titin-nebulin complex is coordinated with the shortening that normally occurs during muscle contraction. The key element of harnessing the absorbed elastic energy is the rate of loading.

For elastic stretch to be utilized in coordination with muscular contractile force, the muscle must be stretched very rapidly and at a high force level. Only then can the two forces combine to produce much more force than either alone. This combined force, the stretch-shortening cycle, is exploited in virtually all force-producing activities, especially in sports.

Running, jumping vertically, and jumping horizontally are all lower-extremity movements critical to sports that rely on the stretch-shortening cycle for maximum force output. Similarly, the acquired momentum of a pitcher’s shoulder stretch, a golfer’s back swing, and a batter’s wind-up all rapidly stretch the eccentrically active involved muscles and then release the stored energy in conjunction with concentric force to maximize resultant effect on ball velocity. Less obvious is the muscle stretching that occurs at the start of a sprint or a standing jump, where the effort against the inertia of the body causes the muscles to stretch slightly before propelling the body forward or upward. This exploitation of the stretch-shortening cycle is critical to virtually every land-based athletic activity.

The key question for athletic performance is whether the valuable properties of the stretch-shortening cycle can be improved through enhanced eccentric resistance training. This question was first addressed by Lindstedt in 2001. Eight weeks of eccentric overload training resulted in a stiffening of the “muscle spring.” He concluded that “not only did eccentric training result in an apparent protection from muscle damage (which would have been severe in naïve subjects exercising at this high intensity), but, significantly, there was a shift in the muscles’ fundamental spring property.”

The increase in the stretch-shortening cycle through accentuated eccentric training was further noted in a review by Douglas in 2017 that concluded, “Eccentric training is a potent stimulus for enhancements in muscle mechanical function, and muscle-tendon unit… architectural adaptations.”

Eccentrics and Muscle Hypertrophy

There is yet another underappreciated role of eccentrics in musculoskeletal health, but it does not involve locomotion. Eccentric muscle actions are the unique source of the signal for mechanotransduction. All musculoskeletal tissues structurally respond to the forces they encounter, either through hypertrophy from high external loading or atrophy in the absence of it. The threshold to create structural adaptation depends on the duration, magnitude, and rate of loading.This was demonstrated in tissue preparations that, when stimulated with concentric muscle force, did not result in high levels of protein synthesis. Only after eccentric activation of muscles did the cascade of protein synthesis occur. It was assessed that tissue deformation is required for significant structural adaptation (Burkholder, 2007).

It is well recognized that mechanical force affects the muscle itself. Increased protein synthesis in muscle occurs not only in the normal maintenance of muscular tissue but also in response to the challenge of supramaximal loads. There are force-sensing structures in the sarcolemma of the muscle cells that can detect the deformation of the cell wall. When triggered, they initiate a cascade of messaging signals that increase the synthesis of contractile proteins.

In the maintenance of muscular tissue, there is a constant balance between muscle protein synthesis and degradation. This represents the normal homeostasis of muscle, and the application of force plays a key role. Too little mechanical stimulation, and the balance tilts toward breakdown of contractile proteins, while increased stimulation leads to its accumulation. In homeostatic control, there is an upper limit of muscle size that can be reached that is basically that individual’s genetically determined muscular size.

As shown in an earlier section, eccentric loading can introduce a superphysiologic signal that invokes a different adaptation process: repair and regeneration. At higher eccentric loads, physical disruption of the muscle fibers can occur and and create areas of micro-injury. Injury is the stimulus for the repair and regeneration processes to proceed. In the muscle, which has innumerable stem cells (satellite cells), this injury stimulates the formation of not only additional myofilaments that increase the force production of the affected muscle but also reconstruction of the cytoskeleton for increased muscle size.

The classic “delayed onset muscular soreness” associated with eccentric loading is directly related to the inflammatory phase of this response. Once inflammation subsides, the process of structural repair can begin, with stem cell migration and protein synthesis. The stem cells provide the substrate required to rebuild and renovate musculoskeletal tissue. The higher the eccentric load applied, the longer the recovery period. The minimum recovery period should be no less than 3-4 days for lighter eccentric loads that approximate the 1RM. For eccentric loading of 50%–80% above the 1RM, recovery can take up to seven days and can be as long as two weeks.

The unique ability of eccentric overloads to create hypertrophy and strength gains was demonstrated in the Lindstedt eccentric studies where “following 8 weeks of training, both muscle strength and cross-sectional area (of biopsied muscle fibers) increased by ~40%.” Subsequent reviews by De Souza Teixeira and the 2017 review by Douglas all reported improved strength gains with eccentric resistance exercise.

Considerations of Eccentric Resistance Application

Thus, in the past few sections, it has been demonstrated how supramaximal eccentric loading is an essential stimulus to increase muscle hypertrophy and improve the elastic behavior of the stretch-shortening cycle. Eccentric training can clearly be beneficial for athletic performance; however, there are practical obstacles to pursuing this course of treatment.

There are three requirements for safe and effective eccentric overload training:

1. The first and most important is that you must never apply a load at such a magnitude or at such a velocity that it could result in physical disruption of the muscle itself.
2. In the goal of structural adaption, you should be able to increase the resistance you apply in incremental amounts over an appropriate period of time.
3. The concentric and eccentric actions are synergistic, and their resistance training should ideally be done concomitantly.

To apply the load safely, as stated in the first requirement, there are two types of external resistance that are not optimal. One is force through a motorized resistance arm that is insensitive to the user’s effort. In this application, a motor pushes a platform, and a subject exerts maximum force against the motor-driven movement arm while the user’s effort is recorded on a force plate. In this closed system, the velocity of the movement arm is fixed and unaffected by the user’s efforts, and the amount of force that the movement arm exerts against the user is essentially infinite, in that no matter how hard the user resists the movement arm, it will continue to apply a high level of force.

There is only one uncontrolled variable in this scenario: the tension in the user’s muscle. As the muscle is forced to lengthen, the internal muscle tension goes higher and higher. In this situation, there is no external control to prevent the tension from exceeding the integrity of the muscle tissue, and unintended overloads can occur.

In addition to high force risk, motorized resistance cannot be increased in incremental amounts, violating the second principle. The basic premise of resistance training in general is the biologic principle of “stimulus response.” The external force stimulates a reponse in the muscle it acts upon. For the adaptation to occur, there must be a period of time for the biologic process to take place. After this recovery period and once the adaptation has occurred, the original stimulus is insufficient to create further adaptation. At this point, the original level of external force is inadequate to cause further structural adaptation. This is the basis of the principle of “Progressive Resistance Exercise” (PRE). It is just as important to apply the principle of PRE to the eccentric phase as it is to the concentric phase.

High-velocity lifting movements pose different risks when the weight is moving concentrically versus eccentrically. When a lifter applies force to a weight concentrically, the energy is transferred into weight, which increases its momentum. Since the weight is moving ahead of the lifter, the increased momentum of the weight does not pose a direct danger. More exertion by the lifter merely accelerates the weight.

The greatest risk of injury is during the lift’s eccentric phase, when the direction of the weight’s movement is against the direction of applied force. In this situation, not only does the lifter have to brake the force of the weight itself but also the additional force created by the weight’s kinetic energy. The formula for the kinetic energy of a mass is:

Kinetic Energy = ½ mass x velocity^2 (velocity squared)

Therefore, a weight traveling at high velocities against the direction of applied force has the potential of delivering many multiples of its resting weight to the eccentrically lengthening muscle. Since the goal of supramaximal eccentric strength training is to deliver a precise amount of force to the elastic zone of muscle lengthening, an uncontrolled speed of descent could easily result in overshooting this desired amount of force, thus risking injury. An example of this is the bench press movement, where the weight is resisted after being allowed to drop suddenly, and the lifter suffers a pectoralis muscle tear at the bottom of the movement (Provencher MT, 2010).

The other less-than-ideal method of eccentric loading is plyometrics with added resistance, such as jump squats. Similar to high-velocity weight lifting, the concentric, or jumping up, portion does not necessarily involve potential danger other than the risk of falling. However, if the landing is done with added resistance, the added kinetic energy of the additional weight can significantly increase the forces absorbed on landing, again risking injury. Additionally, plyometric loading lacks the ability to increase the resistance in accurate incremental amounts that adhere to the principle of progressive resistance exercise.

Simultaneous training of concentric and eccentric muscle function is the most efficient and effective method to increase muscular strength. Share on X

As stated previously, there is a synergy between the concentric and eccentric actions in real-world activities. During the stretch-shortening cycle, both muscle functions are literally on the same molecular framework and work in conjunction with each other. It would therefore be maximally beneficial to perform both concentric and eccentric training in the same movement. This means that an ideal repetition for effective strength training involves a concentric component that is 50%–80% of the 1RM, which then converts to an eccentric resistance that is at least equal to the 1RM. Simultaneous training of concentric and eccentric muscle function is the most efficient and effective method to increase muscular strength.

Considerations of Movements for Eccentric Overloads

Finally, there are clearly some exercise movements that are safer for applying eccentric overloads than others. The danger arises if, during supramaximal loading, the lowering movement pathway is forced to deviate from the track of the concentric movement. The pathway of the movement should be the same for the lighter concentric resistance as for the the heavier eccentric loads.

Virtually all selectorized, single-station machines avoid this risk. The trunk is stabilized in a seat, and the limbs are held in position by pads. The track of motion for the concentric raising of a weight is the same track as for the lowering of the heavier eccentric weight. This consistent positioning ensures that, over a training program with increasing weights, the muscle can adapt and strengthen in a progressive, consistent manner.

There are some free weight exercises that are not ideal for eccentric loading. Clearly, unilateral movements are difficult because the added weight can disrupt the lifter’s balance. There are technical aspects of applying eccentric overloads with dumbbells in general, which make them less effective. Obviously, Olympic lifts with their complex movement patterns are impractical, and eccentrics offer no advantages to improve the performance.

Finally, there could be concerns with the performance of front squats. If it is difficult for an individual to maintain the front squat position, where the line of gravitational pull goes vertically from the barbell through the heels on the ground, the barbell could move in front of this vertical line and create a bending force across the lumbar spine. Accentuated eccentric resistance for front squats should be reserved for lifters experienced with this movement.

However, the majority of basic barbell movements could incorporate accentuated eccentric loading. The basic principle is to place the point of application of the barbell along the gravitational line down to where the body is supported (figure 7). The nature of free weight exercises is such that it is difficult to perform the exercise unless this line is carefully followed.

Of course, in the bench press, the vertical line drops through the shoulders onto the bench. Therefore, most barbell movements can be performed with eccentric overloads (if the safety principles above are followed). Some care is needed with the deadlift as it is sometimes necessary to translate the bar anteriorly to avoid the knees.

Application of Enhanced Eccentric Resistance Training to the Barbell Squat

Training the eccentric portion of the squat is extremely important for absorbing high forces and preventing injury when someone jumps from a height or is placed under a heavy load. In addition, improvements of the stretch-shortening cycle in eccentric squats can result in improvements in the speed and power of most athletic activities. The squat is widely considered to be the single most important movement to train.

The hamstring muscle group plays a major role in the squat’s eccentric movement. By attaching to the ischium, the hamstrings have a long lever arm to exert an effect on hip joint movement. In the case of going deeper into the squat position, the ischium rotates further and further posteriorly, thus effectively lengthening the hamstring muscles. In order to control the deepness of the body’s descent, the hamstrings eccentrically resist lengthening and therefore resist the flexion of the hip joint. The primary role of the hamstrings is not to contract and create hip extension (that’s the job of the gluteus maximus) but to resist and control hip flexion.

A recent issue of the Journal of Functional Morphology and Kinesiology (volume 4/2, 2019) focused on the mechanisms of eccentric muscle exercise adaptations and the emerging applications of this unique form of exercise. In this compilation, accentuated eccentric loading (AEL) was described as an attractive strategy for applying additional stress to the muscle while maintaining the concentric stimulus. The review (Suchomel TJ, 2019) accurately found a paucity of literature on this form of training. In fact, the absence of literature speaks directly to the problem that, until very recently, there was no training equipment developed to provide this important form of resistance.

The absence of literature on accentuated eccentric loading (AEL) speaks directly to the problem that, until recently, there are no training equipment developed to provide this form of resistance. Share on X

In this section, AEL will be described as it is performed on this new technology. The Myonics system (Myonics LLC, Jacksonville, Florida) employs an assistance cable that is attached to the barbell. The cable rises from a new generation of computer-controlled, motion-sensitive motors that can track the movements of the barbell and hence the lifter. The motors can detect if the lifter is moving up or down and are programmed to provide a precise amount of assistance when the lifter reaches certain positions.

In the above scenario, the lifter loads the bar with 250 pounds and then unracks it, and the 250 pounds is lowered in the eccentric phase. Upon stopping at the bottom, the assistance engages, and the effective weight of the bar is only 200 pounds. This weight is raised with concentric strength back to the top position, where the assistance is removed, and the lifter again is supporting the full 250 pounds. Again, this sequence can be repeated for as many repetitions as can be performed.

It is generally recognized that the squat is the single most important exercise to improve overall athletic performance. Combining the muscles of knee, hip, and spine extension, it has functional significance in all land-based athletic activities. As was shown in an earlier section, there are many athletic functions that can be improved by enhancing the stretch-shortening cycle of the lower extremities. Thus, training to improve the eccentric capabilities of the squat will bring additional benefits to athletes.

The implementation of this form of resistance involves many related variables that can complicate the decision-making. These include the amount of eccentric overload resistance, the amount of concentric resistance, the percent difference between the concentric and eccentric loads, and the pace of each movement. Having worked with this system for a number of years, I have arrived at the most practical system for managing these variables.

The system works by using a predetermined percentage difference between the eccentric and concentrics weights. In this way, only the heavier eccentric weight would be entered, and the concentric weight would be calculated by the motor’s computer. For example, after warm-up, a lifter whose estimated or tested 1RM is 500 pounds would have this amount loaded on the bar.

With 500 pounds on the bar, this number is entered into a computerized assistance program. If the program calls for a 25% difference between the eccentric weight and the concentric weight, the motor would supply 125 pounds of assistance. Thus, the lifter would lower 500 pounds, and upon reaching the bottom of the lift, the stopping point is detected and 125 pounds of assistance is generated. The lifter therefore only has to exert 375 pounds of force to return the bar back to the starting position. Once the target number of repetitions is achieved, the strategy is to simply increase the eccentric weight loaded onto the bar and maintain the percentage difference between the eccentric and concentric weights. In the example above, if the eccentric weight was raised to 520 pounds and the 25% difference was maintained (130 pounds), the lifter would raise 390 pounds concentrically.

The Myonics system follows the three requirements of accentuated eccentric resistance; it improves the squat by accentuating the eccentric muscle function. Share on X

This system follows the the three requirements of accentuated eccentric resistance. First, the amount of weight applied eccentrically never exceeds the eccentric maximum, and the risk of injury is minmized. Second, once the desired training effect is reached, the weight can be incrementally increased for the athlete to continue training under progressively increasing resistances. And finally, this system allows for an appropriate resistance to be used for both the concentric and eccentric weights, and they can be trained concomitantly.

Thus, the most important exercise for improving athletic performance can itself be improved by accentuating the eccentric muscle function. Through this training method, athletes can achieve further improvements in sports and athletics.

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…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

Nishikawa KC, Monroy JA, Uyeno TE, Yeo SH, Pai DK, and Lindstedt SL. “Is titin a ‘winding filament’? A new twist on muscle contraction.” Proceedings of the Royal Society B: Biological Sciences. 2012;279(1730):981–990.

Lindstedt JL, LaStayo PC, and Reich TE. “When active muscles lengthen: properties and consequences of eccentric contractions.” News in Physiological Sciences. 2001 Dec;16:256–261.

Douglas J, Pearson S, Ross A, and McGuigan M.  “Chronic Adaptations to Eccentric Training: A Systematic Review.” Sports Medicine. 2017;47(5):917–941.

Burkholder TJ, “Mechanotransduction in Skeletal Muscle.” Frontiers in Bioscience. 2007;12:174–191.

De Souza Teixeira F. “Eccentric Resistance Training and Muscle Hypertrophy.” Journal of Sports Medicine & Doping Studies. 2012;S1(01).

Provencher MT, Handfeld K, Boniquit NT, Reiff SN, Sekiya JK, and Romeo AA. “Injuries to the Pectoralis Major Muscle: Diagnosis and Management.” American Journal of Sports Medicine. 2010;38(8):1693–1705.

Suchomel TJ, Wagle JP, Douglas J, et al. “Implementing Eccentric Resistance Training—Part 1: A Brief Review of Existing Methods.” Journal of Functional Morphology and Kinesiology. 2019;4(2):38.

Training youth athletes always comes with numerous challenges. Middle distance and distance running is no exception and perhaps has more challenges than most sports. The ideals in so much of U.S. culture, especially sports, of “more, more, more” and “no pain, no gain” are particularly dangerous in the world of youth running. The sport is littered with runners who were stars in elementary school, middle school, or high school but do not improve—or worse, never continued to compete because of recurring injuries or burnout.

The ideals in so much of U.S. culture, especially sports, of ‘more, more more’ and ‘no pain, no gain’ are particularly dangerous in the world of youth running. Share on X

We regularly tell the youth runners who we coach (and their parents) that one can assess the quality of a coach not by the success of the runners while running for that particular coach, but by how successfully the runners transition to the next level(s).

It’s easy to say, “kids should not run too much,” but that depends on the age, the physical development of the runner, the running surfaces, the quality of workouts, and more. And, what exactly is “too much?” Do we use Judge Potter Stewart’s guidelines: “I know it when I see it?” There is significant literature on this topic, so instead of reviewing that material, this article will focus on the types of workouts our club does that help young runners maximize what they get out of the workout without having to run more than necessary.

Our club has two distinct groups: a recreational team that focuses on general fitness through running and a racing team that is competitive. The workout philosophy in this article is what the racing team uses, where the runners are predominantly ages 8–14 and the middle school-aged runners generally train with their middle school teams for 6–8 weeks before rotating into the club for the USATF championship part of the season.

Establishing a “Why”

At the beginning of each season, and with each workout, we always have three goals:

1. Have fun.
2. Do your best.
3. Learn something.

1. Have Fun

Understanding what having fun means is easy, and it is foundational to almost every successful runner. If at your core you do not enjoy what you do, it will be hard to excel at that activity for any extended period of time. Enjoy the running. Enjoy being healthy. Enjoy your teammates’ success. Enjoy your team’s success. Enjoy learning. Enjoy getting more comfortable with the fact that running hard can be hard—very hard. Enjoy seeing how your body adapts to training. Enjoy the training process. Enjoy your improvements and your successes, and enjoy what you can learn when you do not achieve your goals. (One will almost always learn more from their “failures” than from their “successes.”) 

Young runners need to be prepared to enjoy the other aspects of running when they aren’t constantly improving; otherwise, performance setbacks and injuries can become debilitating. Share on X

Many youth runners enjoy seemingly endless linear improvement…until they don’t. Young runners need to be prepared to enjoy the other aspects of running when they are not constantly improving; otherwise, performance setbacks and injuries can become debilitating. They need to understand that fast times and strong performances are not the only goal in what they are doing: they are outcomes of all the other aspects of the process. If runners embrace the other aspects of the running process, better times will generally be achieved; but when they are not, the runners can still enjoy all of the other aspects of running so that they do not feel like they failed.

2. Do Your Best

This is much more nuanced than having fun and one of the hardest things for youth runners to do properly. We spend a lot of time explaining what “do your best” means. It’s easy to interpret this to mean run your hardest in every workout, but that couldn’t be further from the truth. Running your hardest in every workout will not only achieve suboptimal results, it can lead to both short- and long-term injuries and burnout. “Do your best” means to do the workout how the workout is designed and the way in which the coach tells you.

Oftentimes—again, especially with younger runners—this means that they need to run at a pace that is easier than they want to, especially at the beginning of the workout. It is very common to see young runners starting out workouts too hard. They then either cannot finish the workout or do the last 25%, 50%, or 75% at a pace that doesn’t help them improve.

The young runners in our club have made great progress in thinking about the workouts in a holistic manner. When we do a workout, the workout is designed to be the entire workout, not half of the workout hard and then barely finish. As they’ve embraced this philosophy, they truly believe what we tell them regularly: if they approach the workout this way, it will be easier for them to do, it will be more fun, they will get more out of it, and they will see better progress with improving times.

3. Learn Something

We regularly over-explain why they are doing what they are doing because we want them to learn and understand. Many of them will encounter coaches who may have the best intentions but just may not be very good coaches. The runners should be able to advocate for themselves in an articulate manner with some basic understanding of the physiology to support their views.

Additionally, learning is about experimenting and understanding their body and how it reacts to different types of workouts and race tactics. They are young. They will make mistakes. But the more they learn now, the better they will be later. This is the foundation of how we approach training with our runners.

The Workouts

The above philosophy, ultimately, has to translate to workouts. We accomplish this through three general types of workouts:

1. Distance runs and aerobic conditioning
2. Intervals/speed workouts
3. Tempo threshold training and core/strength work

While recovery workouts are also critical to the training process, our club only practices 3–4 days a week. (We have a fourth weekly practice on the weekend if we don’t have a meet that weekend.) There are no formal workouts when we don’t meet, and very few of the runners do any informal running on the “off” days. The following sections contain details on how our youth club does this.

1. Distance Runs

Distance runs are a type of workout that can be difficult for younger runners to do correctly, even though “distance runs” for many youth runners may only be 15–30 minutes with occasional short water breaks. It is common for young runners to begin a run at a pace that they may think is not too fast but can quickly turn into a Bataan March, grinding ever painfully slower. A distance run in this manner will lose the desired aerobic benefit of the workout and the adaptation response that the runner should achieve. It is a painful experience and a quick way to turn budding young runners off to the idea that running is fun and something that they want to continue to pursue.

Our club has overcome this with various mantras and strong suggestions. On “distance” days, the athletes hear the words “sometimes a run is just a run,” which encourages them to just go out and have fun running. Another saying we like is, “what your sport does for punishment, we do for fun,” which also encourages the idea that the distance runs should be enjoyable.

Where some coaches and clubs discourage talking and conversation on runs, we strongly recommend that they do exactly that on these distance run days. Share on X

Even more effective, however, is the strong suggestion (very nearly a requirement) that kids run with at least one other runner and that these runs are ALWAYS conversational. We want to see them talking on these runs! Where some coaches and clubs discourage talking and conversation on runs, we strongly recommend that they do exactly that on these distance run days.

2. Interval/Speed Workouts

Speed work and intervals are an important part of every runner’s training. Intervals can vary between longer ‘’strength”-oriented workouts earlier in the season to shorter, faster intervals later in the season. Perhaps the biggest challenge with younger runners is that, as with the distance runs, they start interval workouts too hard.

While it can take some time with each runner, most of the runners in our club learn in one season how to pace themselves in interval workouts to get the appropriate benefit of the entire workout. It helps them understand this concept if the coach explains the workout with a race analogy. If we are doing a workout of three sets of 3 x 300m, just like in a race, if they are exhausted and bent over after any of the first three repetitions of 300 meters, they are running these early repetitions too hard. Like in a 1500-meter race, if they are tired after the first lap, they are running too fast and will have a problem with the race.

They intellectually understand this concept, but it will take a while for them to execute it appropriately. We encourage them to run fast enough on the early repetitions, but they should think about running each set at the same pace or faster than the prior set. And if they feel particularly strong, they can always pick up the pace on the last set or the last few repetitions of the last set. As mentioned previously, if they approach the workouts this way, the workouts will be easier for them to do, they will get more out of the workout, and they will see more and faster improvement with their race times.

We teach our runners that there are four key components to interval workouts that can be changed to accomplish the objectives of any workout:

1. The distance(s) for each interval/repeat
2. The pace of each interval
3. The total distance of the workout
4. The amount of rest between each repetition and each set

To prove this point, in one workout where the runners were questioning the idea, they were told that a very effective early season strength-oriented interval session could be created by using only 100-meter repeats. While skeptical at first, at the end of the first set of 3 x 16 100m repeats, with approximately 30 seconds’ rest between repeats and 2–3 minutes of rest between each set, they quickly realized that, in fact, even though they were never running longer than 100 meters at any time, this was a very effective early season interval workout and not fundamentally that different from other strength interval workouts we had been doing up to that point. Additionally, it provided a nice change of pace for the group and gave them an enormous feeling of accomplishment after they completed the 48th 100-meter repeat!

An additional challenge of most youth programs is that there are a wide variety of abilities with a limited number of coaches. With interval workouts, this means that runners of varying abilities are grouped together, which can be difficult to manage. As the distance of each interval repeat lengthens, it becomes increasingly difficult to ensure that all the runners are getting appropriate rest. This is especially true with the younger or slower runners, who regularly get shortchanged on their rest since they are finishing later than the faster runners but having to start again at the same time as the entire group.

Unfortunately, this dynamic changes the workout materially because either the slower runners don’t get enough rest to run the workout appropriately or the faster runners get too much rest to get the appropriate physiological adaptation desired from the workout. We regularly address this challenge by focusing on the time for each repetition, not the distance. This can be performed effectively in both track and cross country.

We regularly address the challenge of slower runners not getting enough rest and faster runners getting too much rest by focusing on the time for each repetition, not the distance. Share on X

For example, in track, if we are doing an early season strength workout of three sets of 4 x 400m, each repetition ends for all of the runners when the first group completes the repetition, regardless of where each runner is at that specific time. The first group can gauge their progress by their time. The remaining runners can gauge their progress throughout the workout based on where they stop running when the whistle is blown, which may be as far back as 100 meters for some of the runners, in combination with the first group’s time.

When doing 400-meter repeats on the track, starting at the 1500m start works best so that most, if not all, of the runners are finishing somewhere on the turn of the track, not spread out all along the final 100-meter straightaway. With rest being an important component of interval workouts, this methodology ensures every level of athlete gets the most out of their interval workouts.

Tempo Training and Core Strength Work

While distance runs and interval repeats can be hard for young runners to do correctly, tempo runs are perhaps the hardest type of runs to do. Faster than distance runs—but not as fast as intervals—tempo runs are a needle that is hard for most 8- to 13-year-olds to thread. While it may be easy to tell them that the effort for this type of run is one where they shouldn’t be able to talk easily, but they should be able to have short one-sentence intermittent conversations, it’s quite another thing to expect young runners to be able to do this.

To be able to target tempo-run type workouts, we have combined “tempo run paced” intervals with various core bodyweight exercises in a circuit-drill style workout. (It’s also fun running history to recount how Joaquim Cruz, the Brazilian 800-meter gold medalist at the 1984 Los Angeles Olympics, was one of the first runners to popularize this type of circuit workout.) By combining the core bodyweight exercises with repeats (we regularly run 800 repeats followed by a set of five or six different exercises), the runners benefit from strengthening their core and upper body, which is an often-overlooked component of successful middle distance and distance running. But at the same time, the aerobic nature of the core exercises forces the runners to run at a pace that is aligned to the pace and effort for tempo runs: not too hard but not too slow.

While we typically use core exercises like push-ups, crunches, burpees, mountain climbers, and planks, any of a variety of core exercises could be employed. It is important to ensure that the runners use good form for these exercises and adjust either the number or style so they get the muscular benefit of proper form. For example, it can be too difficult for some kids to do clean push-ups. Therefore, it’s better for them to do push-ups with a good, straight back from their knees than to do normal push-ups with terrible form.

Final Thoughts

It’s a fine balance between not running young athletes too much and providing them with a strong foundation that will allow them to be competitive and improve—not only in the short term, but if they want to run and be competitive, for many years and even decades into the future—while having fun doing it.

It’s a fine balance between not running young athletes too much and providing them with a strong foundation that will allow them to be competitive and improve. Share on X

This type of training is designed in line with the philosophy of New Balance Boston Elite Coach Mark Coogan. In his podcast interview with Mario Fraioli on “The Morning Shakeout” (episode 165), he says: “I’ve more come to the conclusion that I’d rather do 20 B+ workouts over 10 weeks instead of having four A+ workouts… I think if I can get the consistency of this B+ type workout – when I do those, I feel like we’re not stressing the body so hard that we’re going to get injured… being really consistent over a long period of time … you don’t have to have any of these super duper workouts to prove who you are.”

While B+ workouts for 8- to 13-year-olds are very different than for Coogan’s New Balance Boston Elite Club runners, the goal is the same: consistent, healthy, and fun long-term running success.

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

Solos smart glasses are an exceptional product for exercise enthusiasts and athletes. I would say the solos technology works best for cyclists, runners, avid walkers, and hikers; you can even track and follow basic resistance training with the solos glasses on to measure your progress. Personally, I rarely use my phone when I exercise outdoors—the most I use is a watch to track my times while I am sprinting, biking, hiking, walking, and on longer runs.

Once I started using solos glasses, it was much easier to track everything and set timers for rest. Also, sometimes I didn’t know what to do for a workout, so I just looked in the solos AirGo™ app and utilized their coaching.

I tested out the glasses while running (long and short distance), walking, and resistance training, and they were comfortable in all forms of training. While running, I did a light recovery jog outdoors and the glasses were comfortable and protected my eyes. I specifically was able to measure my distance (km), step count, and calories (Kcal).

Additionally, I used the glasses at the track doing speed training—through the AirGo app, I was able to time, and it let me know when the rest time was up, and I needed to sprint again. Solos were pretty accurate in all measurements (most technologies will always be slightly varied, especially regarding calories).

While I was doing resistance training (indoors), I used the AI Coaching on the app, which has the option for “core training.” Obviously, not many people will use glasses indoors, but I will say it helps to keep track of reps, time, and sets, and the glasses aren’t bothersome to wear. The user levels are easy, normal, expert, and custom, and all the exercise options are simple and effective and can also be done outdoors anywhere.

Features

The speakers in the glasses are good quality and worked very well, and since they connect via Bluetooth, if you have some form of a coach for the session, you can speak with them or listen to their cueing via the speakers. For example, if you are a remote coach, you can literally run the session via this technology. Or, in a group of cyclists, you can keep in contact with your coach if you are connected to the glasses and the solos AirGo app.

The target range of users varies from novice exercisers to elite athletes, with solos offering many functionalities to match the level of the user, says @bpfitcoaching. Share on X

There was good sound quality on both ends: you can listen to podcasts, Audible, or music and speak to someone on the phone as well. If you don’t like carrying your phone with you while exercising, however, these glasses are not for you. For the glasses to operate, they must be connected to your phone—which means your phone must be close by because of the Bluetooth connection.

You can find many items and gear on the market that can hold your phone while you exercise and keep it in proximity, like a sleeve that runners use to hold their phones on their waist or arm. You also won’t be able to access the AirGo app if your glasses are not on and connected to your phone.

On the aesthetic side, the look of the glasses is styled more like cyclist glasses—for some, these will be similar to what they commonly wear during training, whereas others may be deterred by the appearance.

Setup

It was very easy to set up and track my exercise via the AirGo app, which connects to the Bluetooth on your phone to measure your step count, distance, and calories. There are even different exercise programs like:

• Core
• Posture monitoring
• Stretch exercises
• Reminders
• Interval training
• Cadence training
• Fat burn
• Basic training

This is very inclusive to most of the population for whatever their training goals might be. Coaches can also use these features on their own time whenever they want to train.

In Training

The use of the device and the app was very straightforward; as with most new technologies, I suggest playing around with the app before attempting to put it to practical use. Maybe go for a walk to test out the features to make sure they are functioning.

The target range of users varies from novice exercisers to elite athletes, with solos offering many functionalities to match the level of the user. What is also great is that you can customize your own training and keep track of your progress.

These functionalities are best for more aerobic, HITT, speed, and endurance-style training. Whether you are doing short sprints on the track, interval training on the bike, rowing on the erg, or a light recovery jog, you can keep track of all these styles of training and your progress. For example, as mentioned earlier, the function AI Coaching on the AirGo app has levels ranging from easy to normal to expert to custom.

It is very important to measure progress with training and keep track of as many elements as possible—even small reminders to sit up straight and be aware of posture are crucial. The simple fact that one app includes all this without being confusing is impressive.

Final Assessment

From my own survey of the market, there aren’t many other products exactly like solos, and the glasses are simple enough for anyone to use. The most difficult aspect was setting up the Bluetooth: you must disconnect any other headphones on your Bluetooth before connecting the solos. Once connected, your phone will remember the device.

If you are someone who wants to track your progress in training and utilize everything in one app, these glasses would be suitable for you, says @bpfitcoaching. Share on X

I had a great experience using solos and still do. I continue to utilize the glasses while at the track for my speed training, my longer runs, and when I am hiking, walking, and biking. If you are someone who wants to track your progress in training and utilize everything in one app, these glasses would be suitable for you. The price is fair, and there is no subscription needed to use the app, which I thought was great as well. The biggest takeaway is that this technology will inspire others to exercise, move, and get excited to track their progress.

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

In the last few years, breathing techniques have undergone a renaissance in the world of health and human performance. There is no shortage of social media bagpipes belting out what seems like the latest tunes in strength and conditioning. But when a tool as versatile as breath control presents itself, we have no choice but to listen.

Nasal breathing is an incredibly versatile tool that can enhance conditioning outcomes, create focus and resilience in athletes, provide novelty to training, and even serve as an insight into the CNS. Share on X

Nasal breathing is an incredibly versatile tool that can enhance conditioning outcomes, create focus and resilience in athletes, provide novelty to training, and even serve as an insight into the central nervous system. There’s a great deal of back and forth between opinionated coaches (is there any other kind?) on the inter-webs on whether or not you have to nasal breathe to get good performance outcomes in your athletes. As somebody who has been on the front lines of this work for the better part of a decade, let me clear it up right now—you don’t.

But—and this is a SirMixaLot-sized but—you will leave massive low-hanging fruit on the table for athletic development as well as general athlete health if you fail to understand the fundamental realities of this tool. The problem I see with the general way of approaching this topic at large is that it relegates performance to its outputs alone, and in so doing fails to enhance the precision processes.

You will leave massive low-hanging fruit on the table for athletic development as well as general athlete health if you fail to understand the fundamental realities of nasal breathing. Share on X

Furthermore, this kind of shortsightedness fails to ask: what kind of problems can this tool solve and where could it fit in your toolkit? It’s my hope to provide some clarity and give coaches a sound justification for including nasal breathing in their repertoire, as well as clear suggestions on sensible applications that can be used as soon as you finish reading this article.

Health and How the System Works

Human beings have the ability to walk on both our hands and our feet—but if we have to walk a mile, walking on our feet is far more efficient for even the most skilled Cirque du Soleil hand-balancer. This is due to the fact that the anatomy of the foot and low leg has evolved to use ground force reactions to help conserve energy for forward propulsion.

Similarly, both the nose and the mouth are capable of breathing, but the design of the nose is far better equipped to deal with air and offers layers upon layers of benefit. As such, the nose is the primary anatomical tool for ventilation in nearly all endeavors, and if it causes discomfort to do so, that’s not a design flaw of nature, it’s a health problem that requires resolution.

The nose and its functions are a complex and wonderful system of interrelated miracles that neutralize toxins, contribute to pulmonary function, and guide the formation of the face and jaw through pressure modulation. As one would expect in a complex biological system, when things go really right or really wrong, the ripple from the pebble goes far.

The nose is uniquely equipped to deal with incoming air: it has a filtration system that keeps particulate matter out of the lungs. (My wife and daughter think it’s funny that my personal filtration system is turning gray.) We have a system of mucosa and sinuses that are the ramparts against both bacterial and viral infections. The paranasal sinuses and their associated pressure are also uniquely responsible for the development and stability of craniofacial function and appearance, as well as having a direct impact on vestibular function.

The olfactory system also lives here, and besides the obvious job of regulating the senses of taste and smell, the olfactory system has deep ties to memory and other limbic system functions including the differentiation between safety and threat.

Additionally, nasal breathing provides twice the air flow resistance than that of the mouth and increases tidal volume in the lungs. This trains the diaphragm to become stronger and more pliable, which is an important outcome all on its own. The diaphragm plays an important role not just in respiration but in spinal stability through pressure modulation and is often co-indicated in back pain and instability issues. Controlled nasal breathing during work is a great way to get more bang for your buck and force the trunk to self-organize.

The nose is the primary anatomical tool for ventilation in nearly all endeavors and if it causes discomfort to do so, that’s not a design flaw of nature but a health problem that requires resolution. Share on X

Breathing dysfunction is rampant in both non-athletes and athletes alike. Exercise-induced asthma and sleep apnea are found even among the studliest studs. You may be able to compensate your way to high performance, but believe you me, it is not sustainable, and biology will have the last laugh. Over time, respiratory dysfunction overtaxes the cardiovascular system, reduces sleep quality, and overloads other hormonal and organ systems. There probably won’t be a catastrophic disaster, but you’ll die from a thousand cuts.

Baseline health should be the foundation of human performance, and breathing—in particular, nasal breathing—is a crucial and often ignored component of a holistic performance approach.

Carbon Dioxide Tolerance

I would be remiss to write an article on nasal breathing and fail to mention the essential role carbon dioxide tolerance plays in the whole picture. It’s not within the scope of this article to go deep into this topic, so for now a brief overview will do.

Contrary to popular belief, it’s not low oxygen that signals you to breathe—it’s carbon dioxide (CO2). There are very few sensors in human physiology that indicate low oxygen, but there are a ton of sensors for CO2. Why? Due to the very finite tolerance of pH of the human body. Too acidic? Coma, then death. Too alkaline? Coma, then death.

The body has many ways to regulate pH, but the most energy-efficient way is through the breath. Every breath we take is a management of these variables, and it never stops—especially not during exercise. There’s a feedback loop in the arterial systems (specifically the carotid bodies) that monitors pH and is the thermostat for both the volume and frequency with which you breathe.

When metabolic demands (real or perceived) go up, the system up-regulates the energy delivery mechanisms: heart rate and stroke volume, blood pressure, and, of course, breath rate. The rising levels of CO2 in the blood signal the body to breathe more through feedback loops in the autonomic nervous system. This autoregulation is generally a good thing, because as I mentioned earlier, it keeps us from dying.

However, if we use nasal breathing as an appropriately applied constraint, we can effectively improve general autonomic function and simultaneously improve the efficiency of energy metabolism both during and after work.

So, then, the big question is not really is nasal breathing necessary to improve performance? The question, rather, is how can it be intelligently applied to optimize results?

Practical Application

Nasal breathing can be used as a simple constraint in the training room for multiple effects. Practically, it’s an invaluable tool for use during general, low-to-moderate intensity conditioning, especially in aerobic conditioning that has a relatively low skill requirement.

As an example, a U17 rugby team from New Zealand I consulted with was looking for a way to incorporate breath awareness into their players. They’d tried a few different things up to that point, most of which were too complicated for a bunch of teenagers. I suggested the following: they perform their warm-up laps using nasal breathing only for 2-3 days per week. The team found success not just in getting the boys to comply, but also when they found their pre-practice and pre-game readiness went up dramatically.

Introducing nasal breathing in the warm-up is something I recommend to coaches when starting this with athletes, and it’s something I’ve found great success with in the past. Restricting breathing can be a stressor in and of itself and potentially decrease outputs in the short term. Therefore, it’s essential that you don’t start with something the athlete(s) places high value on, and the warm-up is a great place to get buy-in.

This approach should by no means be relegated to the warm-up only, and nasal breathing during general conditioning activities should be a goal over time. That said, if all training is always nasal breathing, it can rob athletes, especially in a team setting, of opportunities to communicate and build camaraderie. Like any tool, understand what it does and use it when and where appropriate.

Return to Play

Another powerful opportunity to integrate this tool is in return to play (RTP) protocols. There are massive, missed opportunities in RTP in general, and this may be one of the most overlooked pieces of low-hanging fruit there is.

Slow, smooth nasal breathing can be a constraint that keeps athletes from willing themselves through rebuilds in order to get back in action faster. The ability to keep the reins on the breath is a clear and direct line of communication with the deepest part of the nervous system. Using a simple parameter like this creates a real-time dialogue between you, the athlete, and their narrative-free response to treatment/training.

Additionally, using controlled nasal breathing at the reintroduction of progressive workloads can serve as an internal restriction on an athlete’s output during the rebuild. It’s kind of like putting a governor on a motor. You don’t get to go faster until you’ve proven that you’re a good driver. As an addendum to that, working hard while nasal breathing feels like hard work. The confidence of an athlete is directly proportional to how well prepared they feel. This tool gives them a challenge to push up against during rehabilitation to keep their mental edge.

Lastly, nasal breathing is a communication of safety to the deepest parts of the nervous system, which is essential in return to play, and nasal breathing constraints can be an amazing force multiplier for coaches and rehab specialists alike.

If I had a dogecoin for every time I saw a therapist or coach employing a “rehab exercise” while the athlete shook, sweated, and hyperventilated, I’d be a virtual billionaire. The a priori job of the nervous system is to protect us. If we cannot reasonably control breath rate while trying to rebuild a movement skill, the human body will by default build compensatory mechanisms and progress will be blunted.

If we cannot reasonably control breath rate while trying to rebuild a movement skill, the human body will by default build compensatory mechanisms and progress will be blunted. Share on X

Placing breath constraints like nasal breathing during movement reeducation is building two-way communication with the central nervous system. On one hand, it provides an opportunity to listen to what the deepest part of the nervous system is telling us about how it’s perceiving the safety of this movement. On the other, we can coax the nervous system into a place of safety by controlling breathing and thus improve the efficacy of our interventions.

Putting It Together

There are some common pitfalls I’ve experienced and observed over the years that I’d like to share in the hope it will speed up your learning curve with this tool.

1. Too much, too fast. Many athletes I’ve worked with who have a hard time sustaining nasal breathing try to maintain the same level of output in spite of the fact that they’ve put a clamp on the exhaust. This can result in wasted training time, sinus damage, and disappointing bewilderment. Work with your physiology, not against it.
2. Pushing through blockage. If you have a nasal blockage, like a deviated septum or rhinitis, don’t try to force your way through or shove some device up your nose to artificially open things up. Go slow and let your body adapt over time. If you have a serious blockage that needs medical attention, go see an ENT stat.

Short-term tip for sinusitis sufferers: during warm-ups, hum on the exhale. Research shows humming can help subdue acute nasal inflammation through the release of nitric oxide.

Training your nasal passages for progressive loading is just like any other physiological system. Introduce dosage intelligently, with a clear idea of what outcomes you’re looking for and some benchmarks along the way.

Training your nasal passages for progressive loading is just like any other physiological system. Introduce dosage intelligently, with a clear idea of desired outcomes and some benchmarks. Share on X

The rabbit hole of breathing for performance is both deep and wide. Beginning with nasal breathing is a safe and effective way to engage with this process and get the biggest bang for your buck. Nasal breathing is a powerful tool that can enhance athlete health and performance at nearly zero cost to coaches or athletes. If applied with even minimal attention, there are myriad benefits.

Why not try it? You’re breathing anyway.

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. Chaitow, Leon. Recognizing and Treating Breathing Pattern Disorders. Pgs. 11–21.

2. Chaitow, Leon. Recognizing and Treating Breathing Pattern Disorders. Pgs. 45–49.

3. Bianchini, AP, Guedes, ZCF, and Vieira, MM. “A study on the relationship between mouth breathing and facial morphological pattern.” Brazilian Journal of Otorhinolaryngology. 2007;73(4):500–505.

4. Maniscalco, M, Sofia, M, Weitzberg, E, et al. “Humming-induced release of nasal nitric oxide for assessment of sinus obstruction in allergic rhinitis: pilot study.” European Journal of Clinical Investigation. 2004;34(8):555-560.

5. Savulich, G, Hezemans, FH, van Ghesel Grothe, S, et al. “Acute anxiety and autonomic arousal induced by CO2 inhalation impairs prefrontal executive functions in healthy humans.” Translational Psychiatry. 2019;9(1):296.

High-quality speed training can happen without running a personal record (PR). You might be thinking, “well, obviously—PRs aren’t going to happen every day.” But, then, why don’t most coaches and athletes have a mindset that reflects this belief? I’ve seen countless coaches and athletes frustrated by sprint times that weren’t PRs, even though the times were very high percentages of that PR.

To truly evaluate progress, maintain athlete buy-in, and fight PR-itis (the belief that anything that is not a PR is a wasted training rep) with Charlie Francis-inspired long-term speed training, hitting 95% or better of your best threshold is an awesome goal. This threshold simply dictates that a sprint rep that’s 95-100% of your athlete’s best is a high-quality training rep and a good speed day, with under 95% being medium intensity and not fast enough to make the changes most speed training is pursuing.

We can all agree the 95% threshold is good for both the mental and physical sides of speed training, says @CoachBigToe. Share on X

We can all agree the 95% threshold is good for both the mental and physical sides of speed training. However, the questions to ask are not “Is 95% a good percentage?” or “Is 95% too high or too low?” Instead, better questions are:

• “What does the 95% threshold look like with real athletes and real data?”
• “How often are athletes under their 95%?”
• “How does this help me do my job better?”

In this article, I’ll take a dive into:

1. How often athletes are actually under 95% of their best.
2. Which data I drew this conclusion from.
3. How this information can help you be a better coach.

Knowing the Threshold

With any sprint test (a Flying 10, a 15-yard timed acceleration, etc.), multiply your athlete’s best time by 1.05 (5% slower or 95% of their best) and that’s their range to be a high-quality speed training rep. For example, if an athlete’s best Flying 10 is 1.13 seconds, their range is from a 1.13 to a 1.19.

This all makes sense in theory, but what does it look like to actually coach with it?

Here is an example of a chart that could be printed out and posted on a wall in your facility wherever you time sprints.

This all makes sense in theory, but what does it look like to actually coach with it? asks @CoachBigToe. Share on X

Methods

Within the TCBoost facility, I had 38 athletes (23 high school, 13 middle school, 2 college) with at least 10 sprint times of Flying 10’s and/or 5-15’s (15-yard acceleration with timing lasers at the 5- and 15-yard lines). During both the Flying 10’s and the 5-15’s, 28 of the 38 athletes had at least 10 entries, giving me a total of 66 series of 10+ sprint times.

The first entry of each series of sprint times did not have a percentage because it set the PR. If an athlete had 10 sprint times, 9 of those had a percentage of the PR associated with it. In total, this gave me a collection of 1,980 sprint times with a percentage to analyze.

Example Below 95%

The athlete below PR’d 5 of their first 9 sessions (not including the first one), but didn’t PR in the last 10 sessions. A situation like this of early success and late plateaus could lead the athlete and coach to lose faith in each other and stop training. However, with the 95% threshold, there’s a new narrative of what progress looks like: 16 of the 19 sessions were fantastic speed days.

What the Numbers Say

On average, my athletes sprinted at 97.84% of their best time. Within each of the 66 series of 10+ sprint times, only 12.98% of the time were my athletes under 95% of their best. It’s important to note that some athletes spent 0.0% of the time under 95%, while some spent 50% of the time under 95%. A few factors among many that could affect sprint times include:

• Outside sports influencing their readiness and performance;
• Athletes being inconsistent with their coordination and output (believe it or not); and
• Emphasis on coaching/cuing and less on full speed.

It’s remarkable to think about the consistently high outputs athletes are capable of even with all those outside factors that could negatively influence performance.

It’s remarkable to think about the consistently high outputs athletes are capable of, says @CoachBigToe. Share on X

Context of the Numbers

These numbers are specific to my athletes, the facility I coach at, the timing lasers we use, and the speed training we do. There are definitely grains of truth in these numbers, but there is a lot more context that needs to be explained.

The sprint times entered were only my athlete’s fastest ones of that day. The athlete could’ve run the first one just above 95% and all other consequent sprints below 95%. If so, that probably would’ve led to a modification of the session.

The faster the athlete and their PR, the smaller their threshold of 95% is. This could penalize faster athletes and reward slower athletes. An athlete with a PR of 1.00 has a 0.05 range, while an athlete with a PR of 1.50 has a 0.08 range. That’s why this is relative using a percentage of their best.

The faster the athlete and their PR, the smaller their threshold of 95% is, says @CoachBigToe. Share on X

Coaching Solutions: Above the 95% Threshold

If your athlete is sprinting at or above the 95% threshold, stay the course. This means the athlete’s mind and body are in a good enough state to do high-quality speed training that day. Additionally, it’s an opportunity to reassure the athlete that their speed development is on the right path.

Coaching Solutions: Below the 95% Threshold

If your athlete is under the 95% threshold—which doesn’t happen as often as you’d think—there is some gray area in deciding what to do next. First, ask how they’re feeling. When incorporating data into your training, the flow should not run directly from data –> decision. Instead, the appropriate way to apply data follows the model of data –> discussion –> decision. Ask some questions and create a conversation to figure out the context of what could be the potential source(s) of the low sprint times.

If your athlete is under the 95% threshold—which doesn’t happen as often as you’d think—there is some gray area in deciding what to do next, says @CoachBigToe. Share on X

If your athlete looked good during their sprint and says their mind and body are feeling good, run another rep to see what happens. They could’ve needed one sprint to finish warming up, been thinking too much about coaching cues, etc.

If your athlete looked slow and the conversation exposed some factors negatively influencing their readiness to train, move on to something else. There are a variety of other ways to develop speed besides all-out timed sprints. An active recovery session could be the most valuable thing you can do for your athlete that day. Pushing forward with direct speed work could do more harm by causing excessive fatigue.

Key Takeaways

It’s incredible to know that in only about 1 out of every 10 speed sessions my athletes might not be ready for a very speed-intensive session. Meaning, an overwhelmingly large majority of the time, it’s a great day for speed training.

An overwhelmingly large majority of the time, it’s a great day for speed training, says @CoachBigToe. Share on X

Knowing that athletes are not under 95% of their best as often as you might think, when it does happen, there are probably big causes negatively influencing their performance. It’s your job to be a detective before the sprints happen. Starting off each session with a simple question or two about how their day was and how ready they are to train starts giving you clues. The clues aren’t necessarily for how good their performance will be, but rather if you should be extra conscious of their first one or two sprints.

If my athlete is under their 95% threshold, I don’t end the session right away or throw my hands up in frustration. All I do is ask how they’re feeling and what’s been going on the last few days. I have my coach’s eye, my athletes know their bodies best, and the 95% threshold is just another tool in the toolbox (yes, I just rolled my eyes as well). Those three things contribute to my decision-making process by opening up discussion.

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

Speed training is a layered, multifaceted process dependent upon a range of factors. Whether linear or multidirectional speed, there are physical, technical, rhythmic, and mental components that will impact success. One piece of this layered process is the strength and stability of the trunk and spine.

When I say the trunk and spine, I refer to the areas of the midsection, lower back, and pelvis. This goes beyond having strong abdominal muscles and needs to be addressed with more than just ground-based ab exercises. Particularly when performing aggressive speed drills that involve high intensities, quick changes of direction, or sudden decelerations, the trunk and spine could be a key limiting factor and potentially even a link leading to an injury down the road.

Strength and stability of the trunk and spine goes beyond having strong abdominal muscles and needs to be addressed with more than just ground-based ab exercises. Share on X

This area needs to be prepared and strengthened with the utmost intent and specificity to not only help the athletes achieve the most out of drills but also to round out their physical capabilities and support injury reduction in any way possible.

When to Implement Trunk and Spine Training

When beginning to integrate trunk and spine training directly into speed sessions, coaches can simply place it within the preparation to help ready the athletes for the session ahead.

Another option would be to utilize the exercises in the session itself and complex or superset them with the speed drills. Doing this could help enhance the drill being performed and make it task-specific at a muscular level. We want to be able to make direct connections with our athletes and have exercises carry over for one another.

Pairing a particular trunk and spine exercise, such as an isometric hold, can help raise the body’s threshold or ability to prevent movement in that particular range, in the hope that it can also carry over when the athlete performs the speed drill again. Additionally, these drills are fantastic to include in a training design because they can be done right outside on the field!

An example would be using a band stabilization exercise to train a specific isometric in between reps of an athlete running sprints (if the coach feels this is appropriate, as each situation is different).           

Simply using the exercise as active recovery between reps is efficient and preferable to having athletes just stand around for their recovery. Yes, they need to rest, and this rest can be several minutes depending on the speed of the athlete and the distance covered, but we also know:

• The perceptions of sports coaches regarding time between reps.
• Parents may not understand this amount of rest in training.
• Total time is a limiting factor.

Also, having a determined, overzealous athlete sit for four minutes can be the most daunting task of the session, no matter how much logic you offer them.

While I will always defend my programs and sessions in a constructive way to those I work for, incorporating the trunk and spine exercises as active recovery is a win for everyone. The exercise isn’t physically taxing enough to hinder their next sprint, is beneficial enough to not waste anyone’s time, and makes a positive impact.

Incorporating trunk and spine exercises as active recovery is a win for everyone. The exercise isn’t physically taxing enough to hinder the athlete’s next sprint and makes a positive impact. Share on X

Band Stabilization Series

There is no limit to band stabilization exercises, as you can perform these exercises in a variety of ways. You can alter the position of the athlete from a kneeling to a split squat position (and everything in between), as well as where the band is anchored to the athlete. Anchoring the band around the waist allows for multiple angles of pull and anchoring the band around a single-sided shoulder allows for forward and backward motion. When going over the shoulder, the athlete will have their arms up and elbows back, making two “L’s” if we were to look down on them. Doing this helps prevent trunk rotation and fires up the upper back.

The band can even be anchored around the leg to attempt to pull the limb into a specific position, forcing the athlete to counterbalance this and work their way out. This is usually only performed in special circumstances, such as with a now-cleared athlete with a previous injury history.

When applying the resistance, I recommend going right up to the point where the athlete feels they will lose the position being held. Pull right up to that line but be careful not to cross it or you will pull the athlete over onto the ground. Going right up to the line will be uncomfortable for that athlete, though, and you may see some breakdown of position; if so, just slightly release some tension or coach them back into position.

Perform each hold for 10-30 seconds, progressing either by moving onto the next position or increasing band tension.

Video 1. Full Kneeling Position

When going from the full kneeling position, the closer the knees are together, the more difficult it is for the athlete. Widening the knees creates a wider base and more stability. 

Video 2. Half-Kneeling Position

Be mindful during the half-kneeling position to keep monitoring the down knee and keep the body symmetrical, as the leg will occasionally rotate in or get into all sorts of positions depending on how much resistance is given. The resistance can be applied to either side with the knee being down.

Video 3. Split Squat Position

The split squat position is by far the most difficult position listed here and can be performed off either side of the leg that is up. Aligning your athletes on a line can help them maintain proper body positioning of the lower body throughout this exercise if needed.

Video 4. Glute Bridge Position

The glute bridge is performed from a stronger position, so athletes can do this movement with more resistance than the others. It can be progressed by using a heavier band or taking it into a single leg stance.

Some other exercises that you can use to blend trunk and spine training into your speed sessions are resisted marches and skips.

Single Arm Band or Sled Walks

You can use a resistance band or light sled to start incorporating more dynamic exercises to challenge the trunk and spine.

I would first recommend performing these exercises with a resistance band as opposed to a sled because you can better manage the resistance added during the exercise and adjust it if needed. You can use a single resistance band or tie a couple of bands together to better distribute resistance slowly. Loop the resistance band around the athlete’s shoulder and apply just enough resistance so the athlete feels challenged and the band is trying to pull them to rotate to that side.

The exercise should be performed forward and backward. Cues for both directions are to focus on walking a straight path, with a slight lean in the direction you walk, while keeping everything in linear alignment: feet, hips, and shoulders, pointed as straight ahead as possible.

The athlete keeps their arms up and pulls their elbows back, making it easy to spot trunk rotation but also get some upper-body stability involved. If this position alone is too much for the athlete, have them simply place their hands behind the head in a prisoner position. This regressed version offers more stability.

Video 5. Band Single Arm Walks—Forward and Backward

Athletes are genuinely surprised how difficult this is if they do it correctly, and a little resistance goes a long way! Once the athlete has progressed to perform the exercise on a sled, I typically start even my strongest and fastest athletes with just 25 pounds loaded on the sled.

When using the sled, it’s easiest to loop the belt or harness of the sled around the shoulder and perform the same way. With the sled, though, the weight is what it is—there is no adjusting during the exercise, so the athlete has to remain stable and must not stop moving.

Video 6. Sled Single Arm Walks—Forward and Backward

Perform these exercises for sets of 20-40 yards, as fatigue begins to quickly affect proper body position.

Another movement to perform with the sled or bands is a drag using a single-arm isometric hold. Using a single arm forces the opposite side to remain stable, so if I’m performing the exercise with the handle in my right hand, my left side needs to contract and lock me in to prevent unnecessary movement.

Video 7. Sled Row Isometric Hold Back Walk

Weighted Offset Marches and Skips

Offset, weighted exercises such as marches and skips blend the weight room with more rhythmic and fluid drills such as skipping.

When performing these exercises, hold a kettlebell or dumbbell ranging from 5-30 pounds in one hand. The weight chosen will depend on the exercise being performed—skips are more difficult than marches and isometric holds—and you also need to consider the capabilities of the athlete.

Perform these movements for 10-20 yards, focusing on proper body posture and alignment and preventing the chest from collapsing down or crossing the knee or foot over the body’s midline. Athletes can perform these exercises in two positions:

1. By holding one weight by the side, in a suitcase carry position.
2. On one side held up in a front rack position.

Weighted Offset March Holds

Performing the offset march position in an isometric is a great way to introduce the movement and begin building a base from the ground up. While holding the implement on one side, the opposite side leg will raise, and the athlete will hold this position for the desired time.

This should be performed on both sides and done from each position: suitcase and front rack. Hold anywhere between 10 and 30 seconds per side to begin.

Video 8. Weighted Offset Marches Iso Hold

Weighted Offset Marches & Skips

Once the athlete is comfortable with the isometric position, slowly began progressing them to movements. Regardless of the variation or position, the universal cues will be having a strong, upright posture, popping the thigh up off the ground to about hip height rapidly, and maintaining a consistent, fluid, rhythmic timing throughout the exercise.

Some common errors I see during these exercises are body posture and coordination going everywhere. Even those athletes who can perform skips perfectly may struggle with the addition of the load.

When progressing this offset series, I would begin in the suitcase position first and move from marches (slow/fast) to skips (individual/continuous) before concluding with power. Then, moving through the same series from the front rack position.

Of course, this could appear differently depending on the situation and athlete, but that is a logical setup to use.

Video 9. Weighted Offset Marches and Skips—Suitcase Position.

Video 10. Weighted Offset Marches and Skips—Front Rack Position.

Video 11. Weighted Offset Power Skips.

The Next Level

Integrating trunk and spine training into speed sessions can be simple yet take your athletes and your sessions to the next level. Placing these movements into the athlete’s preparation or complexing them with specific exercises can help correct postural weaknesses and raise the body’s threshold during high-speed drills.

Integrating trunk and spine training into speed sessions can be simple yet take your athletes and your sessions to the next level. Share on X

These exercises can be performed directly out on the field with just a resistance band, sled, or a few weights and begin the necessary process of blending the weight room and field.

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