Is lifelong endurance training associated with maintaining levels of testosterone, interleukin-10, and body fat in middle-aged males?

BACKGROUND: Aging is associated with a gradual physiological decline, including an imbalance in hormone profile, increased adiposity, and reduced anti-inflammatory cytokines. However, lifelong physical exercise mitigates aging, as observed in endurance-trained middle-aged athletes (EMA). AIM: We compared and associated testosterone, interleukin 10 (IL-10), and body fat in EMA and untrained age-matched individuals (UAM). METHODS: Participants were EMA (n=25; 51.48±9.49 years) and UAM (n=23; 46.0±9.37 years). Both groups underwent body composition measurements (evaluated by a skinfold protocol) and blood sampling for IL-10 (assessed through ELISA(®) kit) and testosterone (assessed with Roche Diagnostics(®) kit, Mannheim, Germany, by chemiluminescence technique in a third-party laboratory). RESULTS: EMA had lower body fat (14.15±3.82% vs. 23.42±4.95%; P<0.05), higher testosterone (751.68±191.45 ng/dL vs. 493.04±175.15 ng/dL; P<0.05), and higher IL-10 (8.00±1.21 pg/mL vs. 5.89±1.16 pg/mL; P<0.05) compared to UAM. A significant linear correlation was found between testosterone and IL-10 (r=0.56; P=0.001), whereas significant inverse correlations were observed between body fat and testosterone (r=–0.52; P=0.001) and body fat and IL-10 (r=–0.69; P=0.001). CONCLUSIONS: EMA had higher levels of IL-10 and testosterone and lower body fat in comparison with UAM. In addition, higher IL-10 was associated with increased levels of circulating testosterone and lower body fat. RELEVANCE FOR PATIENTS: The adoption of endurance training as part of a healthy lifestyle may contribute to decreasing age-related testosterone reduction, besides reducing markers of inflammaging, preventing the occurrence of chronic age-related diseases, and thus contributing to healthy aging. For people who already have chronic diseases, physical exercise can shift the immune system toward a more anti-inflammatory profile and, thus, improve their pathological condition. In both cases, physical exercise can help attenuate the decline in testosterone, decrease body fat, and increase anti-inflammatory levels.