Effects of acute HMB-FA supplementation on antioxidant status and muscle damage in Elite Judoka: a randomized pilot trial

High-intensity judo bouts induce oxidative stress and muscle damage, impairing recovery. This randomized, double-blind, placebo-controlled pilot trial examined whether acute β-hydroxy-β-methylbutyrate free acid (HMB-FA) supplementation influences muscle damage, oxidative stress, and antioxidant biomarkers in elite judoka.

Twenty-two male elite judoka were randomized to HMB-FA (1.0 g BetaTOR®) or placebo. Supplements were ingested after four simulated Olympic judo bouts. Blood was sampled pre-exercise, post-fourth bout, and 2 h post-bout for creatine kinase (CK), lactate dehydrogenase (LDH), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), malondialdehyde (MDA), and total antioxidant capacity (TAC). Twenty-one completed the protocol (one placebo dropout due to injury). Data were analyzed via 2 × 3 mixed ANOVA with partial η².

No group differences were seen for CK, MDA, or TAC (p > 0.05). Significant group × time interactions were observed for CAT (p < 0.001), GPX (p = 0.031), and SOD (p = 0.025), indicating greater enzyme increases in HMB-FA (CAT + 54%, GPX + 38%, and SOD + 16%) than placebo (+7-14%). LDH declined in both groups (interaction, p = 0.001), but more so in the placebo group (-29.9%) than in the HMB-FA group (-18.6%).

Acute post-exercise HMB-FA supplementation in elite judo athletes did not significantly influence muscle damage or oxidative stress markers but transiently increased antioxidant enzyme activities (CAT, GPX, and SOD). These findings suggest an enzyme-specific effect and highlight the need for future studies using more precise oxidative-stress markers and cellular assays to better evaluate antioxidant responses; however, these effects should be interpreted with caution due to potential limitations related to assay sensitivity and the timing of measurements.