Plasma cortisol and testosterone responses during a collegiate swim season

Plasma testosterone (T) and cortisol (C) measures were examined in swimmers in response to a 500-yd time trial conducted on five occasions (T1-T5) during a collegiate season of training and competition (21 weeks). The 6 male distance swimmers performed the time trials during transitions in their training regime. Preexercise blood samples were obtained following a 15-min equilibration period in a supine posture. After a standardized warm-up, each athlete completed the 500-yd time trial. Postexercise blood was taken within 1 min of completion with the swimmer in a supine posture. Pre- and postexercise T tended to rise progressively during the season, accompanied by a concomitant progressive decrease in the average daily training volume. Preexercise C concentrations were reduced (p < 0.05) at T2 and T5 compared to the beginning of the season (Tl). However, the molar ratio of T/C was unchanged during the season. These hormonal measures may be useful in tracking training status and responses in selected individuals.