Sex-specific changes in metabolic and musculoskeletal biomarkers after acute resistance exercise in healthy young adults

Exercise induces acute biochemical signaling between muscle, bone, and adipose tissues that may influence whole-body metabolism and musculoskeletal adaptation. This investigation examined sex-differences in concentrations of circulating biomarkers associated with metabolic and musculoskeletal regulation before and after an acute resistance exercise test. During baseline assessments for a longitudinal exercise training study, 37 participants (22 males and 15 females) completed an acute resistance exercise test consisting of a 6 set × 10-repetition back squat at 75% of their one repetition max. Blood samples were collected before and immediately after the acute resistance exercise test to quantify biomarker concentrations. Total body DXA determined body composition. Sex-differences in absolute changes from pre- to post-exercise in biomarker concentrations were examined. After adjusting for baseline lean mass, a significant interaction was observed for irisin ( p = 0.043); concentrations increased in males (∆1.1 ± 0.3 µg/mL, p < 0.001) but not females ( p = 0.515). After adjusting for baseline bone mineral content, a significant main effect of time (∆12.7 ± 1.5 pmol/L; p < 0.001) was observed for sclerostin. After adjusting for baseline fat mass, significant interactions were observed for leptin ( p = 0.040) and high molecular weight (HMW) adiponectin ( p = 0.003). Leptin concentrations decreased in females (∆−7.9 ± 2.5 ng/mL, p = 0.004) but not males ( p = 0.689). HMW adiponectin increased in females (∆630.5 ± 194.8 ng/mL, p = 0.007) but not males ( p = 0.213). A significant interaction was observed for insulin ( p = 0.004), which increased in females (∆9.7 ± 2.1 μIU/mL, p < 0.001) but not males ( p = 0.426). A significant main effect of time was observed for glucose (∆1.8 ± 0.3 mg/dL; p < 0.001). Sex-specific changes in biomarkers associated with metabolic and musculoskeletal regulation were evident following acute resistance exercise and may explain differences in health and adaptation.