Skeleton, the sliding event in which athletes race down an ice track head first, is a fast-paced and punishing sport. Skeleton racers can reach speeds of 125 kph (~80 mph) during their descents. This is a little slower than the feet-first luge, in part because the skeleton sled runs on circular bars rather than sharp runners.
Body positioning is key in the sport. It’s the athlete’s primary method of steering, and it controls how much drag slows them down. But skeleton runs are brutally taxing; athletes pull 4 or 5g in the turns – more than astronauts experience during a launch! All that jostling means athletes cannot stand more than about 3 trips down the track in a day. To practice positioning without the bone-jarring descent, athletes can work in a wind tunnel. While the wind tunnel provides the aerodynamic equivalent of their usual speed, athletes focus on holding their bodies in the most streamlined position. Some wind tunnels are even able to provide screens that let the athletes see their drag values in real-time, letting them adjust to learn what works best for them. (Image credit: N. Pisarenko/AP, Bromley Sports)