CoQ10 flops as a sports supplement: no gains in VO2max or recovery markers

Heavy training generates oxidative stress, which has been proposed as the link between big training loads, cell membrane damage, impaired recovery and inconsistent performance responses. That theory has made antioxidants a marketing goldmine, and coenzyme Q10, a cofactor in the mitochondria's energy machinery and a fat-soluble antioxidant, is widely promoted to athletes on exactly this logic. The randomised evidence has always been inconsistent, though. This review set out to pool it properly and test whether CoQ10 delivers anything measurable.

The authors searched PubMed, Web of Science, Embase and EBSCOhost up to April 2026 for randomised trials of oral CoQ10 in athletes or trained individuals, registering the review in advance. Twenty-four studies with 613 participants were included, of which 15 studies covering 330 participants contributed to at least one pooled analysis. Because some studies supplied more than one eligible comparison, effects were counted at the comparison level and pooled with random effects models. Risk of bias was judged as some concerns in 23 of the 24 studies and high in one.

The primary pooled analysis, on the oxidative stress marker malondialdehyde, was not statistically significant. A sensitivity analysis did favour CoQ10 on that marker, but the authors describe the signal as fragile. The headline physiological outcome, VO2max, was flatly neutral, and pooled analyses of blood pressure, creatine kinase, interleukin-6, total antioxidant capacity, tumour necrosis factor alpha and anaerobic threshold were all neutral as well. The narrative synthesis hinted at more coherent signals in studies conducted under marked oxidative or recovery stress, but nothing quantitative backed that up.

This is the pattern antioxidant supplements keep producing in sport: a plausible mechanism, enthusiastic marketing, and pooled trial results that fail to show a performance effect. The single wobble in a biochemical marker under a secondary analysis does not rescue the case, and the authors caution against reading much into it. What remains genuinely open is whether athletes under extreme training or recovery stress respond differently, a question the current small and methodologically limited studies cannot answer. Better designed trials in exactly those contexts would settle it.

If CoQ10 sits in your supplement stack for performance or recovery reasons, this pooled evidence gives no support for that use in trained people. Aerobic capacity, muscle damage markers, inflammation and blood pressure all sat still. The only hint of benefit was on one blood marker of oxidative stress, in a secondary analysis the authors themselves call fragile. That is a reasonable basis for scepticism the next time the antioxidant pitch appears on a label.