Can MTHFR help with Sport?

The question of whether MTHFR helps with sport is poorly supported by evidence. MTHFR is a gene involved in folate metabolism and homocysteine regulation. Variants like C677T can elevate homocysteine, which might theoretically impair blood flow and recovery. However, no robust studies show a direct performance benefit in athletes. Most claims come from nutrigenetic marketing rather than solid science. A DNA test for MTHFR alone is insufficient to guide training or diet. Established factors like training load, nutrition, and recovery are far more impactful. For those concerned about homocysteine, ensuring adequate folate, B12, and B6 intake is sensible regardless of genotype. The evidence level is 'unclear' or 'marketing'.