Surgeries that were once repairs are now reconstructions, enabling athletes to return to the field sooner and even better. Novel prostheses are allowing maimed soldiers to compete at the elite level of sports. Researchers of motor skills and pain tolerance, who once relied on crude measures, now study brain imagery to analyze neural activity. Many long-held axioms of sports physiology have been exposed as myths. And yet, as always with serious scientific inquiry, the journey so far has shown us how much farther there is to go—and how much more there is to learn.