When we hear about the pain of conditioning, it usually means acidosis in the blood, or a rise in lactate accumulation. Lactate is a by-product measured by sport scientists or coaches to evaluate workouts and profile athletes during fitness testing. Lactate is not the cause of fatigue, but does correlate with the decay of work, thus making it a biomarker for performance.
In this article, I share my own experience with lactate testing and why it may still be relevant, even with the growing market of non-invasive options such as the Moxy Monitor. Lactate testing isn’t just for endurance sports—it’s useful for speed and power events, as well as team sports.
I break down everything you ought to know about lactate testing, and share a few practical guidelines for coaches that want to get started. I don’t use lactate testing with everyone I work with, but once in a while the information makes a difference and does make me rethink what I am doing. If you are trying to get the most out of your training and want to try lactate testing, the cost and effort aren’t so much that you can’t do it on your own.
What Is Lactate in the Blood?
Lactate is a normal by-product in the body, and is instrumental in fueling during intense activities. During workouts, the uncomfortable burn in the muscles isn’t from lactate, but likely from the hydrogen ions resulting from the drop in the body’s pH. The pain of conditioning is related to lactate, but the cause of the discomfort and residual pain afterward is more about middle damage than acids in the bloodstream. For years, lactic acid was an abused term and a scapegoat for fatigue, instead of being viewed as a normal part of biochemical reactions in the body. Lactate isn’t a waste product—think of it as part of the recycling of biochemistry to help cope with fatigue.#Lactate is a normal by-product in the body, and instrumental in fueling during intense activities, says @spikesonly. Click To Tweet
During the early 2000s, the thought process on lactate changed it from foe to friend, as the research hinted that without lactate, the metabolic processes during conditioning would be impaired. After seeing lactate in a new light, some coaches began to believe that lactate itself was actually either directly anabolic or a biomarker that indicated specific adaptations were taking place. This paradigm shift from enemy to saint was just as problematic, as new myths created new confusion.
Lactate is an important biomarker, as disruption to the pH in the blood is a possible sign that instrumental work for athletes is taking place. An increase of lactate in the blood could signal an increase of endorphins and the occurrence of other physiological responses, and it’s a great workhorse biomarker for sport scientists and coaches alike.
In the second edition of Better Training for Distance Runners, a classic book on training for endurance, David Martin wrote a fantastic summary of lactate. On page 99, he states:
“We know it is an important energy source, released from both FT and ST skeletal muscle cells and usable as a fuel especially by the ST muscle cells. This site is not some kind of gremlin molecule to be maligned as an internal poison. Rather, it is produced in a well understood manner as usable as an important energy source.”
I will talk about fiber types and how lactate responses are unique to each athlete later, but to me the above summary is the heart and soul of understanding lactate in sports science. Even if the book is decades old, the science is pretty much on point and very effective in explaining the nuances of the biochemistry of lactate.
What Is Lactate Testing?
Lactate testing samples blood from a lancet, used on the finger, earlobe, or other part of the body. Lactate testing is considered lab testing, even if it’s practical and portable for field tests, simply because it is invasive. Lactate testing must be done with gloves due to the fact it’s actually testing the blood of an athlete. Most of the time, lactate testing is done with endurance athletes to calculate their lactate threshold, or the intensity of experience before the lactate increases exponentially. Appropriately called the lactate inflection point, or LIP, many athletes and coaches still use the zone of intensity, but it’s no longer considered as useful as it was 10 years ago.
Lactate testing isn’t just for endurance sports and graded conditioning tests; sometimes coaches use it for intervals and real-world testing conditions like shift evaluation during ice hockey. Sport practitioners also use lactate testing to determine the responses to speed and power work, like repeated or absolute sprints and weight training responses.
Any time a change in pH is expected, lactate testing is a great total body summary of what is occurring. Lactate testing isn’t a local muscle test like EMG; it’s a global indicator of intensity from work. Resting lactate tests are sometimes done for medical purposes, but those are not sports performance tests. Proper athlete evaluation uses some resting baseline testing, and evaluations of athlete responses to incremental training factor in those resting numbers.Lactate testing isn’t a local muscle test like #EMG; it’s a global indicator of intensity from work, says @spikesonly. Click To Tweet
Many lactate tests take place in conjunction with gas exchange testing, meaning traditional VO2 assessments are performed with blood testing. You can do other field tests, such as intervals or recovery-style testing, to estimate the work response, but those are not gold standards. Even a high-quality portable lactate analyzer is roughly half a mmol off in accuracy, so view those numbers as applied values only. Applied values are useful for comparison, but do not replicate actual lab values.
Lactate responses to exercise follow a similar trend as heart rate; thus, many coaches decide to skip lactate responses and go right into heart rate training. While understandable, lactate responses and heart rate monitoring are not interchangeable. Also, short exposure intervals are not sensitive enough to use as indicators of change, as heart rate is not a replacement. In fairness, effort and intensity do have enough parallels to make a case for coaches to use heart rate monitoring as a way to see the internal response from workouts.
How Can Lactate Testing Help Athletes?
The primary benefit of lactate testing is getting a simple summary of how the body is coping with the workload for comparative purposes. Arguments against lactate testing do have merit, as nobody awards an athlete for the best lactate reading. The physiological responses are not as important as the hard measures, like speed and pacing, but lactate measurements keep coaches honest.Arguments against lactate testing do have merit, as there is no award for the best #lactate reading, says @spikesonly. Click To Tweet
It’s easy to get too liberal and wide with prescription training—you eventually need to have workouts that do exactly enough to get the results, but not too much that they overtrain the athlete. Lower levels of lactate training, such as scholastic levels, may not be necessary. Elite-level lactate testing still has a role, and many companies in the sports technology space have tried to replace lactate meters with non-invasive options such as near-infrared spectroscopy (NIRS).
The most important trend that coaches look for is adaptation to the work being placed on the athlete. If the same workload is easier for the body, the athlete is increasing their fitness. Different pathways may cause this improvement, such as running efficiently, a change in mitochondria, or more efficient cooling or fueling strategies, but a change is a change.
I have come up with a pragmatic three-step approach to lactate testing for athletes. It’s not special, but it does work. It uses the concepts from The Science of Winning, written by Jan Olbrecht, while maintaining a practical coach’s approach to implementing the data. In fact, the book is long overdue for being on a Top 10 list, and deserves its own book review as it’s a classic.
Produce it: Lactate numbers don’t mean anything unless you know how to drive up effort maximally. Most coaches think lactate testing means finding a lactate threshold, and while that is important for some base work training, the best way to create adaptation is to push the body harder. Developing maximal output is usually a limiting factor more than sustaining a submaximal level, so I focus on how fast first rather than capping the level of effort.
Reduce it: Once speed and conditioning are sufficient, seeing how the system adapts to training is possible. Coaches want to see an athlete able to reduce their lactate response with the same load, or go faster with the same lactate reading. Lactate readings are not the same as heart rate recovery, but they do show a pattern of adaptation that is helpful for coaches.
Use it: The final phase is athletes feeling comfortable with heavy doses of lactate coursing through their muscles, and this is when both the psychological and physiological benefits start to surface. While technically, athletes utilize lactate biochemically from day one, athletes will learn over time to use the enzymatic reactions in training to get more quality work in. Lactate priming isn’t potentiation, but it’s a way for athletes to create a biochemical groove that they can maintain in training.
This methodology is not a perfect physiological model of how the lactate response interacts with sports development, but it’s solid enough to get results. There is no use in getting lactate readings without a training model that will work with any metric, so focus on the structure of training versus one data point. What I do like about the above model is that it’s a focus away from threshold models and centers on a speed model.#Lactate adds a layer of personalization and precision to training that is too compelling to dismiss, says @spikesonly. Click To Tweet
Developing speed interests me far more than lactate tolerance does. Still, it’s important to add context to the velocities you achieve in sport so you can calibrate sessions. Lactate adds a layer of personalization and precision to training that simply is too compelling to dismiss.
Why Athletes Have Unique Lactate Responses
Athletes have their own individual lactate profile—which shows their physiological response to a given workload. Many variables interact with lactate responses, such as a small change in technique for example, making interpretation a true combination of art and science. Each athlete will have various fiber type differences, mitochondrial adaptation patterns, hormonal profiles, and psychological factors that require attention. Even the same athlete will test differently with different diet strategies, so the lactate response is not just about looking at the differences between two tests.
The replication of bread-and-butter workouts with tremendous attention to detail will make or break lactate testing. Still, within reason, consider lactate tests strong evidence of adaptation when you follow testing protocols. Lactate blood tests are invasive, but they are valid and reliable when properly administered.Within reason, #LactateTests are strong evidence of #adaptation when you follow testing protocols, says @spikesonly. Click To Tweet
Most of the genetic factors that determine the lactate response can be attributed to muscle fiber type and similar. In general, lactate production mirrors power production, and the Jochums model of training is one example of how lactate can be seen as a way to gauge output rather than fitness.
Athletes with dramatically different aerobic abilities can have similar lactate readings because many qualities of an athlete sometimes cancel out when the rubber hits the road. A great example of this is with muscular strength and repeated sprints, as an athlete can use their leg strength to perform while another athlete can use aerobic contributions. Both athletes may have similar speeds, but they create those velocities and fatigue patterns much differently.
Basic Guidelines with Mobile Testing
If you want to get started with lactate testing, I recommend visiting a local university and experiencing a lab-quality lactate evaluation. The primary reason I recommend this is that the protocols are standardized and more likely to give you a good indication of how stringent the testing process is. During the process, you can see firsthand about cleanliness and data capture, and experience the nuances of what it takes to get great data and even see your own threshold.
The most important parts of testing are safety and keeping a protocol strict and tight for data integrity. Most lab tests are for endurance, specifically for running, cycling, and rowing. Swimming tests are done on the deck of a regular pool, but some high-tech pools are like water treadmills and are useful for gas exchange and lactate testing.
Graded testing is a process that incrementally increases the speed or output of an exercise, and is useful for those wanting to know the anaerobic and aerobic thresholds. The threshold concept is an estimated point of when the body is physiologically unable to match the metabolic demands of the given pace. Technically, both the anaerobic and aerobic thresholds are special milestones, but they are moving targets because diet and hemoglobin concentration in the blood, as well as total hemoglobin mass, can influence them. Mitochondrial density and production influence the results of graded testing, so most of even the best laboratory testing is still an estimate of what is changing. Even a change in footwear could influence a running test.
Pilot studies or experiments outside conventional lab tests are still viable alternatives to the dry and endurance-style options like graded testing. While graded tests do everything they can to control the environment to nail a specific inflection point to lactate, the opposite occurs with field tests. Field tests evaluate workouts, not specific physiological metrics of the body.
Sport scientists can perform strict laboratory tests for formative evaluation, or use more practical estimates of lactate production with intervals or timed sampling of blood. The logistical demands of blood testing in “the wild” are complicated not because of safety and equipment, but because simple things like athlete sweat can dilute samples. Working fast is necessary as well, since a mere 20 seconds can alter the outcomes of the test.
Handheld lactate meters are inexpensive and can evaluate workouts such as repeated sprints or longer periods of activity such as practice drills and even weight training. A rise in lactate is a great biomarker, but high lactate levels don’t indicate the occurrence of strong aerobic development. For example, many bodybuilding circuits create an enormous increase in lactate, but nobody expects that extra work in the weight room will build a cross country skier or marathoner. Still, alternative forms of training that both challenge the aerobic system and raise lactate levels provide enough data points to make reasonable conclusions on how the body is being challenged, especially in cyclical activities like circuits.
Software for lactate testing is usually primitive, simply because it’s just a line plot and calculating a lactate threshold isn’t difficult. Due to the convenience of treadmill running tests, most of the calculations are automated after the collection of data and a simple one-page summary is usually provided if you do concierge service style testing with a commercial lab. Most athlete management systems can calculate thresholds and overlay other data points like heart rate and oxygen utilization.
Getting Started with Lactate Testing
If you decide to perform lactate testing, you will need a lactate meter and plenty of lancets and test strips. Lactate testing is not appropriate for everyone, as invasive testing requires safety precautions and you can’t do it in groups without a lot of time and help. Additionally, if you are not familiar with lactate readings and how workouts connect to the numbers, lactate testing is just a burden, and not helpful to the training process.
Plenty of successful programs in sport have used lactate testing religiously and done well with it because it provides objective information. Heart rate and perceived exertion are nice proxies to lactate testing, but are not the same.Heart rate and perceived exertion are nice proxies to #lactate testing, but are not the same, says @spikesonly. Click To Tweet
If you feel that lactate testing can help you, getting started requires around a few weeks of practice and about a thousand dollars a year for a few athletes. Lactate testing isn’t for everyone, but if you are serious about finding everything you can about how training connects to the internal physiology of your athletes, lactate testing might be a great fit.
Editor’s Note: Appreciation to Lorena Torres-Ronda for her photos.
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