What role does Homocystein play in Sport?

Homocysteine is a sulfur-containing amino acid produced during methionine metabolism. In sports, its role is primarily discussed as a marker of cardiovascular health and methylation status. Elevated homocysteine levels can impair endothelial function, increase oxidative stress, and potentially hinder recovery after intense exercise. Acute physical exertion may transiently raise homocysteine, whereas regular endurance training tends to lower it, likely due to improved methylation capacity and better B-vitamin status (folate, B6, B12). There is no evidence that homocysteine directly enhances athletic performance; rather, high levels are considered detrimental for long-term health and recovery. The evidence base consists of observational studies and small intervention trials, not large RCTs. For athletes with a family history of cardiovascular issues or poor diet, checking homocysteine may be useful, but it should not replace medical evaluation. Genetic testing for variants like MTHFR has limited predictive power because lifestyle and nutrition are the dominant modulators.