What role does Selen play in Sport?

Selenium is an essential trace mineral that plays a key role in antioxidant defense via selenoproteins like glutathione peroxidases, which protect cells from oxidative damage during intense exercise. It also supports thyroid hormone metabolism and immune function, both relevant for athletic performance and recovery. However, direct evidence for selenium supplementation improving sport performance in well-nourished individuals is limited. Most studies show benefits only in those with deficiency. Excessive selenium can be toxic (selenosis). Therefore, a balanced diet (Brazil nuts, fish, eggs) usually suffices. Genetic variants in selenoprotein genes (e.g., GPX1, SEPP1) may influence individual requirements, but testing is not standard. Overall, selenium's role is supportive, not ergogenic. Athletes should consider checking their status before supplementing.