Rama, L., Alves, R., Rosado, F., & Teixeira, A. (2009). Salivary and plasma cortisol and free testosterone during a winter swimming training season. A paper presented at the 14th Annual Congress of the European College of Sport Science, Oslo, Norway, June 24-27.

This study measured the response of salivary and plasma cortisol and free testosterone during a swimming winter season, in order to test the sensitivity of these markers to training variation, fatigue, and adaptation. Well-trained swimmers (M = 13; F = 6) had training load, volume, and intensity and participation in competition events, monitored during 29 weeks of a winter swimming season. Blood and saliva samples were taken at rest, at the same time of day, before the first afternoon workout of the week, and at four testing moments: before the beginning of the training season (t1), after the first seven weeks of incremental training loads (t2), after six weeks of an intermediate intense training mesocycle (t3), and after a major competition (t4). Salivary cortisol and testosterone were determined. At t2, t3 and t4 the Ss completed a graded swimming protocol (7 x 200 m), to determine the lactate velocity curve and associated parameters. This study was a single-group repeated-measures design in which the Ss served as their own controls.

Training volume was significantly higher at t2 and t4 and intensity increased significantly at t4. Plasmatic and salivary cortisol showed significant correlations at all testing moments. Male Ss had higher plasma and salivary cortisol values in harder training phases when compared to t1. Salivary and free plasmatic testosterone were also significantly correlated at the four testing moments but showed no variation during the training season. When compared to the beginning of the season, salivary testosterone:cortisol only decreased significantly at t4, but in the case of plasmatic testosterone:cortisol, significantly lower values at all intermediate moments of the season were found when compared to the initial value. The results of the graded swimming protocol revealed that the highest maximal and range of swimming velocity were observed at t3 which coincided with the highest salivary cortisol and lowest testosterone:cortisol values.

Implication. Free testosterone levels are not affected by training during the swimming season. High cortisol levels did not impair maximal and submaximal performance capacity. The stress induced by hard training phases increased cortisol values both in plasma and saliva, but a real increase in the magnitude of the training load is needed to have a significant impact in salivary cortisol content. Salivary cortisol at rest could be a marker of training-load stress.

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