This subject necessarily involves digging deep into sensitive topics like race and gender. Epstein explores controversial questions such as - Are black athletes genetically predetermined to dominate both sprinting and distance running, and are their abilities influenced by Africa's geography? Are there genetic reasons to separate male and female athletes in competition? Should we test the genes of young children to determine if they are destined for stardom? Can genetic testing determine who is at risk of injury, brain damage, or even death on the field? Through on-the-ground reporting from below the equator and above the Arctic Circle, revealing conversations with leading scientists and Olympic champions, and interviews with athletes who have rare genetic mutations or physical traits, Epstein forces us to rethink the very nature of athleticism.