Is Homocystein useful for Sport?

Homocysteine is a biomarker relevant to sports primarily as an indicator of methylation status and B-vitamin sufficiency (folate, B6, B12). Elevated homocysteine is associated with oxidative stress, endothelial dysfunction, and increased cardiovascular risk—factors that can impair recovery and long-term performance. Some studies report an inverse relationship between homocysteine levels and VO₂max, but the evidence is inconsistent. There is no strong evidence that lowering homocysteine (e.g., via B-vitamin supplementation) directly enhances athletic performance. The benefits are likely preventive and related to general health rather than ergogenic. Genetic variants (e.g., MTHFR C677T) can affect homocysteine metabolism and should be considered when interpreting test results. For athletes, maintaining normal homocysteine is sensible, but routine testing or supplementation without medical indication is not recommended. Evidence: mixed (human-observational, mechanistic). Caveat: No proven direct performance benefit; high-dose B-vitamins may cause adverse effects.