Clara Hughes

Hughes is the only athlete with multiple medals at both Summer and Winter Games: two road cycling bronzes in Atlanta in 1996, then four long-track speed skating medals from 2002 to 2010, including 5000m gold in Turin. Endurance cycling and distance skating share a crouched position and sustained aerobic power, and she switched between them so effectively that she returned to the road for London 2012 at 39.