Biomarkers to enhance training and performance
Conference Highlights from ACSM’s Annual Meeting, June 2022
Written by: Nancy Clark
The annual meeting of the American College of Sports Medicine attracts not only sports science professionals from the US, but also from around the globe. At this year’s Meeting in San Diego (June 2022), more than 3,000 people shared their knowledge and latest research. Dr. Shawn Arent PhD CSCS*D, FISSN, FACSM, FNAK, exercise physiologist and Chair of the Department of Exercise Science at University of South Carolina, focuses his research on the relationships between physical activity, stress, health, and performance. Here are some highlights from his talk on Biomarkers to Enhance Training and Performance.
Why measure biomarkers?
A biomarker is a measurable substance in an organism whose presence is an indicator of normal biological processes, disease, infection, or environmental exposure. Biomarker data can be used to assess performance, recovery, and training optimization. Endocrine biomarkers measure stress and adaptations to training. Biochemical biomarkers measure muscle damage and inflammation. Nutritional biomarkers measure the impact of diet, such as on blood glucose and iron levels. Biomarkers are best used to document changes over time, as opposed to taking one measurement such as serum ferritin, to see if the measurement simply falls within normal limits.
The military and some professional athletes and/or teams are very interested in measuring biomarkers. That said, some pro players might not want to be “monitored” if the biomarker information will determine whether they get drafted or has impact on their contract negotiations. After all, if you don’t know a problem exists, then you don’t have to deal with it! That said, biomarker changes can be related to injury risk; preventing injury can prolong careers. Connecting biomarkers to measurables like performance, training, sleep, and diet provides context and meaning to the measurements.
Biomarkers and diet
Biomarkers can be used to see the physiological impact of low energy availability. Changes in biomarkers can help convince weight-conscious athletes that calories are not bad but rather essential to enhance performance. When a player knows how many calories they burn, they can then understand how much they need to eat. Biomarkers show how well they recover when well fueled.
We now know that an energy deficit can be more detrimental than sleep deprivation, and that many markers can take a full month post-dietary restriction to get back to normal.
—With Army ranger training, a 1,000 calorie per day deficit reduced testosterone and increased cortisol.
—With a 1,200 vs 1,000 calorie deficit, even a 200-calorie difference impacted the degree of change in biomarkers. A re-feed temporarily restored both IGF1 and T3.
Biomarkers and stress
Both physical and psychological stress impact biomarkers. For example, travel is stressful for athletes. Biomarker measurements suggest that travel through time zones is brutal for athletes. Seeing sleep data can help athletes learn the value of sleep.
Biomarkers suggest that pre-season soccer training is very stressful, akin to playing 10 games in 14 days in some cases. That is way too much stress on the body. Pre-season damage means the competitive season is spent trying to keep the players in the game. A longer pre-season could alleviate this problem (if coaches and players buy into biomarker research).
To date, there is no agreed upon set of biomarkers associated with over-reaching and over-training. The best predictors of over-reaching / over-training have typically been the psychological changes—but are psychological changes the first to change? Or are there biomarkers in the blood that can assess changes? It appears that biomarkers may be the earlier indicators of over-reaching / over-training than changes in performance (such as a decline in vertical jump).
The wave of the future
Athletes interested in getting their biomarkers measured should know this emerging field has yet unanswered questions, including:
—What is the best time-course for measuring biomarkers? Should recovery markers be measured right after exercise? Or a day later? For example, the acute effects of cortisol are different than the chronic effects, so putting a measurement into context is critical to be able to take the data and turn it into wisdom.
—How often should measurements be taken? Biomarkers can predict and confirm changes in training status, but we need to know the time course of changes. Researchers should carefully select what to measure, so they get information they can interpret (as opposed to collecting as much data as possible and then figuring out how to use the information). Over-measuring places a burden on athletes who can then become less willing to cooperate.
—Should athletes avoid exercise the day before blood draws/data collection? Or should they do their regular training?
—Will coaches be willing to alter training schedules based on biomarkers? Coaches’ buy-in is essential.
—Do biomarkers differ when measured under research conditions? That is, how does data from exercise tests in the lab compare to a highly competitive event such as a semi-final soccer match?
—What is the minimal performance-enhancing level of a biomarker? Is higher better? When is a level too high? How low is too low?
—Can biomarkers predict and prevent illness? In an 8-week basic training study, a third of the subjects whose biomarkers classified them as being over-reached experienced illness. By keeping athletes healthy and in the game, the likelihood of a winning season improves.
—How do oral contraceptives impact biomarkers? Limited research suggests oral contraceptives may impact physiological responses to training and competition, with non-users having a greater increase in muscle mass and losing more body fat during a season.
With time and well-established protocols for measuring biomarkers, this evolving field will have a significant impact on improving the health and performance of members of the military, professional athletes, and curious consumers who can afford this luxury.
Author
Sports nutritionist Nancy Clark MS RD CSSD has a private practice in the Boston-area and is author of the best-selling Nancy Clark’s Sports Nutrition Guidebook. For more information, visit www.NancyClarkRD.com.
