This study examined the influence of 10 days of intensified training on salivary cortisol and testosterone responses to 30-min, high-intensity cycling (55/80) in a group of male elite triathletes.
Seven elite male triathletes (age 19 ± 1 y, V̇O2max 67.6 ± 4.5 mL · kg–1 · min–1) completed the study. Swim distances increased by 45%. Running and cycling training hours increased by 25% and 229%, respectively. REST-Q questionnaires assessed mood status before, during, and after the training period. Unstimulated saliva samples were collected before, after, and 30 min after a continuous, high-intensity exercise test. Salivary cortisol and testosterone concentrations were assessed.
Compared with pretraining, blunted exercise-induced salivary testosterone responses to the posttraining 55/80 were found (P = .004). The absolute response of salivary testosterone concentrations to the 55/80 decreased pretraining to posttraining from 114% to 85%. No changes were found in exercise-induced salivary cortisol concentration responses to the 55/80. REST-Q scores indicated no changes in the participants’ psychological stress–recovery levels over the training camp.
The blunted exercise-induced salivary testosterone is likely due to decreased testicular testosterone production and/or secretion, possibly attributable to hypothalamic dysfunction or reduced testicular blood flow. REST-Q scores suggest that the triathletes coped well with training-load elevations, which could account for the finding of no change in the exercise-induced salivary cortisol concentration. Overall, these findings suggest that the 55/80 can detect altered exercise-induced salivary testosterone concentrations in an elite athletic population due to increased training stress. However, this alteration occurs independently of a perceived elevation of training stress.
Hough is with the Dept of Sport and Exercise Sciences, University of Bedfordshire, Bedford, UK. Robertson is with the School of Human Movement Studies, Charles Sturt University, Bathurst, NSW, Australia. Gleeson is with the School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.