The effects of an exercise training on steroid hormones in preadolescent children – a moderator for enhanced cognition?

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 t₁ to t₂ were predicting higher working memory performance post-intervention (β = 0.45, R² = 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.