The ruling prevents Caster Semenya, 28, an elite runner and Olympic champion from South Africa, from competing in those races because her testosterone levels are naturally very high. The science underpinning that decision is complicated, raising difficult questions about biology, fairness and gender identity. What is testosterone? It’s a hormone, an androgen, that has a variety of effects on the body. Women and men produce testosterone, but women don’t make nearly as much.

Source: International New York Times May 01, 2019 22:24 UTC