Abstract
This study investigated the effects of 20-hydroxyecdysone (20E) derived from Asparagus officinalis extract on substrate utilization and metabolic health in young males undergoing resistance training (RT). Twenty healthy males were randomly assigned in a double-blind design to receive either a placebo (PLA; n=10) or 30 mg/d of 20E (n=10) for 12 wk, during which all participants performed supervised RT three times per week. Assessments were conducted at baseline and post-intervention, including body composition, substrate utilization, fasting glucose, insulin, free fatty acids (FFAs), and the quantitative insulin sensitivity check index (QUICKI). The 20E group showed significant reductions in arm (p<0.01), leg (p<0.05), and abdominal fat (p<0.05), with arm fat reduction significantly greater than in the PLA group (p<0.05). Fat oxidation increased at rest and during exercise in the 20E group (p<0.01), with between-group differences evident only at 40% of V•O2peak (p<0.05). Furthermore, 20E supplementation was associated with favorable metabolic changes, including reductions in fasting insulin (p<0.01) and plasma FFAs (p<0.05), alongside an increase in QUICKI (p<0.01). These findings suggest that 20E supplementation, when combined with RT, may support regional fat reduction, promote fat oxidation, and improve insulin sensitivity, thereby offering potential benefits for metabolic health.
