Watch the Olympic 50m freestyle, 20 seconds of breathless chaos

As swimming rolls on at the Summer Olympics, Friday will bring us several men’s and women’s heats in the 50m freestyle. Get ready to watch it and feel tired.

Here’s a video of someone swimming this race. Watch his face:

In the 50m free, swimmers dive into the water and crawl as fast as they can for one length of the pool. That’s the entire race. And most of them do it without breathing.

Breathing is an essential part of human life. Holding your breath is hard. As I sit here writing out this post, I just tried to hold my breath, and I lasted about 35 seconds.

The swimmers in the 50m freestyle will probably need a bit more than 20 seconds to get from end to end of the pool. That’s a manageable amount of time for a person to hold his or her breath, at first glance. But then, factor in that these Olympians are racing against the fastest swimmers in the world and moving their arms and legs as rapidly as possibly.

A swimming race is chaos on the human body. The swimmers we’ve gotten to watch in the pool in Rio are some of the most physically fit humans alive, and they’re always gasping for breath by the end of their races. A 50m heat is a short one. I get tired just by thinking about trying it without any new oxygen entering my body. The controlled chaos in the pool is going to be nuts, and it'll be easy to forget that these athletes are not breathing.

The women’s preliminary heats in the 50m free are on Friday afternoon, and the semifinals happen Friday night, just after the men’s final in the event. Nathan Adrian and Anthony Ervin are the United States' gold medal shots on Friday.

Here’s an estimated schedule for Friday, with all times Eastern.

Women’s 50m freestyle
Preliminary heats: 12:02 p.m. (Stream)
Semifinals: 9:59 p.m. (Stream)

Men’s 50m freestyle
Final: 10:44 p.m. (Stream)