If you've tuned in to the Olympics this week, there's a good chance you've noticed the big, purple bruises on some Team USA athletes, like Michael Phelps, from cupping. Now, it looks like another mystery has emerged, this time specific to swimmers: why do they wear two swim caps?
You may have noticed that swimmers like Katie Ledecky, who shattered her own world record on Sunday night, end up peeling two of the caps off in the seconds after the end of a race. As a report by Yahoo Sports explains, there are at least two practical reasons why the athletes double up on the special headwear: two caps are more stable and they don't interfere with speed.
Turns out that while the lower swim cap fits on a swimmer's head better, it can wrinkle and create drag, which could very well create the split-second difference between getting a medal and getting nothing. To combat this, many swimmers layer on a second cap made of a silicon material and often wear their goggles between the two caps as well, according to the report. Of course, there may be other factors like comfort, for example, and there are certainly some swimmers who wear only one cap.