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Biomarker Testing for Athletes: Health, Performance and Recovery

By Heidi Strickler | May 28, 2019, 8:34 a.m. (ET)

Biomarker testing

If you could predict and prevent the onset of an injury or illness, would you?

This is exactly what companies like Ireland-based Orreco are offering with their comprehensive biomarker testing and analysis. 

Injuries are common among triathletes, and they cost you more than training sessions and personal records. A 2015 study published in the Scandinavian Journal of Medicine & Science in Sports studied the economic burden of injuries on runners in the lead-up to an event (1). Of the 53 athletes in the study, 32 reported 41 running-related injuries, 85% of which were caused by overuse. From the data, the researchers estimated that running-related injuries incur a total average cost of $106.51 (1).

The average cost of a redox biomarker kit to measure inflammation (and illness/injury risk) is $25. 

Unlike race fees and training equipment, costs from injury and illness can be avoided. Athletes walk a fine line between achieving peak fitness and allowing for adequate recovery. Unfortunately the latter is often neglected, ultimately side-lining an athlete with injury, illness, or overuse. However, advances in science and technology now offer athletes, coaches, and members of the sport science team the opportunity to predict and prevent negative health and performance outcomes and individualize training and nutrition to optimize health, recovery and performance. Gone are the days of ‘trial and error’ thanks to the availability of athletic biomarker testing. 

What is biomarker testing?

A biomarker is defined as “any substance, structure, biological process, or product of a biological process that can be objectively measured in the body, and influences or predicts the incidence of an outcome or disease” (2). Proteins, hormones, metabolites, electrolytes, and numerous other small molecules serve as biomarkers, although some are more validated in athletes than others (3). A comprehensive performance set of biomarkers should include key indicators of:

  • nutrition and metabolic health
  • hydration status 
  • muscle status
  • cardiovascular and endurance performance
  • injury status and risk 
  • inflammation

Every athlete is unique in their response to training load, sleep, diet, and stress. This explains why you and your training partner use the same training plan but one of you sets a personal record and the other ends up with an injury. Biomarker analysis tracks the above key indicators, predicts negative responses and optimizes health, performance and recovery through individualized training cycles (3).

What Type of Testing Should I Get? 

Biomarker testing is meant to be individualized. This means that each athlete may benefit from a unique set of tests, and there is not a “one size fits all” panel. Gender, age, training status, weight history, medical history, diet history, injury history, sport, season, training load and genetics are all factors that determine which biomarker indicators are right for you. 

The most common nutritional deficiencies seen in endurance athletes include vitamin D, iron, folate, vitamin B12, and magnesium, all of which can result in reduced endurance performance and muscle function. Frequent monitoring of these micronutrient biomarkers may help identify individual deficiencies and track changes, especially as training volume and nutritional demands increase.

Tracking hydration status over a number of days can shed light on whether or not fluid and food intake is maintaining euhydration. This is best done using urine specific gravity (USG) during critical times in training, during travel, and before and after competition.

Due to the oxidative nature of exercise, inflammatory biomarkers such as CRP and interleukin are valuable. The relationship between DHEA and cortisol is a useful marker of susceptibility to overtraining in the female athlete. These types of biomarkers need to be measured at multiple time points throughout training, off-season, and competition cycles. To assess chronic changes across a season, athletes may be tested every four to six weeks under similar conditions (3).

Stress fracture risk has been reported to be as much as 50% higher in female athletes when compared to their male counterparts (3). Insulin-like growth factor (IGF-I), one biomarker associated with bone quality, has been reported to be positively associated with bone mineral density. 

When should I get biomarker testing? 

Single measurements cannot offer comprehensive insight into health or help predict overtraining due to the sensitivity of the biomarkers and individual variation in “normal” values. Identified biomarkers should be tested strategically throughout the course of the training year (3). Here are some tips for doing this.

  • Test on multiple days during the off-season. This establishes your baseline. 
  • Test at the beginning and end of training season transitions. This establishes normal ranges as you move into a change in training load.
  • Test around (before and/or after) a single hard session during the competitive season. This red flags abnormalities in biomarker response to acute stress. 
  • Test before and several times following a major competition. This helps determine recovery capabilities, and helps bridge the gap between “feeling” ready and recovered and the body’s true state of recovery. 

Testing type and timing should also take into account an athlete’s subjective feedback. If something feels terrible, or feels awesome, biomarker testing can help provide insight into the reason, and adjustments to training, sleep, nutrition, and recovery can be made as appropriate. 

Where Can I Get Biomarker Testing? 

If you’re interested in getting biomarker testing and want to learn more, visit Orreco’s website to read the latest research and view testimonials from athletes. If you’re not near an Orreco office (California, Ireland, or England) and can’t find reputable companies in your area, eNRG Performance offers various mail-in biomarker test kits. eNRG Performance Registered Sports Dietitians can help guide you in which test will best suit your needs, and testing packages come with a consult to help you interpret your results and provide evidence-based training and nutrition recommendations.

A higher training load, more ice baths, and the latest endurance supplements are no longer enough to give you a performance edge. Stop playing trial and error with your health, performance, and recovery. As we say at eNRG Performance, "Test. Don't guess."

Heidi Strickler, RD, CSSD, METS I, ISAK I is a Registered Sports Dietitian with eNRG Performance. An avid endurance athlete, triathlete, and ultra-runner herself, she has a passion for providing nutrition coaching to endurance athletes. She also specializes in plant-based nutrition, female physiology, and collegiate athlete nutrition. In July, she will graduate with a Master’s degree in Sports Nutrition from Liverpool John Moores University in England, United Kingdom. Find out more about Heidi at

The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.


1. Hespanhol Jr., L.C., van Mechelen,W.,Postuma,E., Verhagen, E. (2015) Health and economic burder of running-related injuries in runners training for an event: A prospective cohort study. Scandinavian Journal of Medicine & Science in Sports, 26(9):1091-9. 

2. Strimbu, K. and Tavel, J.A. (2010) What are biomarkers? Current opinion in HIV and AIDS, 5(6):463-6. DOI: 10.1097/COH.0b012e32833ed177

3. Lee, E.C., Fragela, M.S., Kavouras, S.A., Queen, R.M., Pryor, J.L., Casa, D.J. (2017) Biomarkers in sport and exercise: tracking health, performance, and recovery in athletes. Journal of Strength and Conditioning Research, 31(10):2920-37.