OBJECTIVE Research demonstrates a variety of cognitive benefits induced by different chronic physiological stressors (e.g . motor vs. cardiovascular exercise training) and acute exercise to affect steroid hormone secretion, the present study aims to investigate 1 .) motor vs. cardiovascular exercise training and their impact on salivary Testosterone, Estradiol and Progesterone and 2 .) whether alterations in steroid hormones might moderate exercise-induced cognitive benefits .
METHODS In a randomized control trial, 71 preadolescent children (39 girls) at the age of 9-10 years were randomly assigned to a cardiovascular exercise group (CE), a motor exercise group (ME) as well as a control group (CON) in which students were attending assisted homework . The participants attended their program three times per week, for a total of 10 weeks . Steroid hormones in the saliva, working memory performance and state-trait anxiety levels were determined before and after the intervention .
RESULTS Statistical analysis showed no chronic changes in hormones through the interventions . Stepwise hierarchical regression revealed the Testosterone*ME-interaction to be a significant moderator for working memory performance post-intervention (β = 0.48, p = 0.014). Within the ME, increases of Testosterone from t to t were predicting higher working memory performance post-intervention (β = 0.45, R = 0.16, p = 0.038).
CONCLUSION Our findings suggest 1 .) that motor-exercise-induced cognitive benefits are moderated by changes in Testosterone and 2 .) that a 10-week exercise training of moderate intensity and with a motor demanding vs a cardiovascular character does not affect the chronic concentration of salivary Testosterone, Estradiol and Progesterone nor anxiety levels in preadolescent children.