Prior research has illustrated that high volumes of aerobic exercise result in a reduction in basal concentrations of testosterone in men. These prior studies have mostly been conducted on recreational runners and identified reduced testosterone, but not concentrations low enough to be considered pathological. Therefore, the purpose of this study is to assess the basal concentrations of testosterone and cortisol in elite triathletes, as well as assess the impact of a World Championship race on the acute responses of these hormones.
22 men (Age: 40.6 ± 11.5 yrs; Height: 179 ± 6 cm; Weight: 77.0 ± 7.0 kg) who participated in the 2011 Ironman World Championships served as subjects. Resting blood samples were taken 2-4 days prior (BL), as well as immediately (IP), 1 day (D1) and 2 days (D2) following the event, and were later analyzed for total testosterone and cortisol concentrations.
At BL, of the 22 subjects, 9 men had a normal testosterone concentration, while 9 men fell within a 'grey zone' and 4 other men demonstrated concentrations suggestive of deficiency. Testosterone was significantly lower than BL at D1 (95% CI=0.10-0.34, P<0.001, ES=0.53) and D2 (95% CI=0.01-0.21, P=0.034, ES=0.35). Cortisol was significantly different from baseline at IP (95% CI=1.07-0.83, P<0.001, ES=8.0). There were significant correlations between time and age (R = 0.68, P=0.001) as well as baseline testosterone and cortisol (R=0.51, P=0.015).
Elite ultra-endurance athletes may demonstrate not only reduced testosterone, but sometimes clinically low concentrations that could be indicative of androgen deficiency.
International journal of sports physiology and performance. 2018 Jun 28 [Epub ahead of print]
David R Hooper, William J Kraemer, Rebecca L Stearns, Brian R Kupchak, Brittanie M Volk, William H DuPont, Carl M Maresh, Doug J Casa
1 Department of Kinesiology, Jacksonville University, Jacksonville, FL., 3 Department of Human Sciences, The Ohio State University, Columbus, OH., 2 Department of Kinesiology, University of Connecticut, Storrs, CT., 4 Department of Military and Emergency Medicine, Uniformed Services University of Health Sciences, Bethesda, MD.