Salivary cortisol and testosterone responses to resistance and plyometric exercise in 12- to 14-year-old boys

This study examined changes in salivary testosterone and cortisol following resistance and plyometric exercise protocols in active boys. In a crossover experimental design, 26 peri-pubertal (12- to 14-year-old) soccer players performed 2 exercise trials in random order, on separate evenings, 1 week apart. Each trial included a 30 min control session followed by 30 min of either resistance or plyometric exercise. Saliva was collected at baseline, post-control (i.e., pre-exercise), and 5 and 30 min post-exercise. There were no significant differences in the baseline hormone concentrations between trials or between weeks (p > 0.05). A significant effect for time was found for testosterone (p = 0.02, η p 2 = 0.14), which increased from pre-exercise to 5 min post-exercise in both the resistance (27% ± 5%) and plyometric (12% ± 6%) protocols. Cortisol decreased to a similar extent in both trials (p = 0.009, η p 2 = 0.19) from baseline to post-control and then to 5 min post-exercise, following its typical circad...