The dose–response effects of hydrolyzed curcumin on recovery, inflammation, and oxidative stress following exercise-induced muscle damage in males

This study investigated the effects of two dosages (750 mg and 1500 mg) of hydrolyzed curcumin on physiological recovery following exercise-induced muscle damage (EIMD). In a randomized, placebo-controlled, double-blind design, 34 recreationally active males (27 ± 6 years; 180 ± 7.3 cm; 82 ± 11.3 kg) were assigned to three groups: PLA (2 × 750-mg/day placebo), LOW (1 × 750-mg/day curcumin + 1 × 750-mg/day placebo), and HIGH (2 × 750-mg/day curcumin). Supplements were delivered in 15 mL gel sachets over 7 days, starting 48 h before EIMD. The EIMD protocol involved 8 sets of 10 repetitions at 110% of one-repetition maximum on the leg press, with 5-s eccentric phases and assisted concentric phases, targeting the quadriceps. Recovery was assessed pre, post, 24, 48, and 72 h post-EIMD via the Free Oxygen Radical Test (FORT), creatine kinase (CK), interleukin-6 (IL-6), isokinetic peak power, and a muscle endurance test (sustained isometric contraction at 50% peak torque). The HIGH group showed significantly greater reductions in pain, CK, FORT, and IL-6 (p < 0.05), but slower muscle endurance recovery at 24 h compared to LOW. Findings suggest a dose-response effect, with higher curcumin doses improving biochemical recovery but potentially impairing performance recovery.