50 Fittest Female Athlete in the World with Bonus (Instagram)

48. Ireen Wüst / SPEED SKATING

The 30-year-old Dutch long-track allround speed skater has insane stamina and endurance, which she trains by participating in another sport: cycling. Like many other professional speed skaters, Wüst works her legs on the bike to prepare for longer distances on the track, and she also hits the gym for lifts such as box squats, which develop hip power and explosiveness.