Kaylyn Brown and the USA mixed 4x400m relay team broke a world record...in an Olympic heat

Kaylyn Brown ran so fast in the mixed 4×400-meter relay that the other runners never stood a chance.

I won’t even pretend to understand what kind of speed you have to possess to be on an Olympic track and field relay team. But, apparently, Team USA has a lot of it. They were already well on their way to likely winning a 4x400m relay race when Kaylyn Brown ran the anchor leg of her life Friday.

As she rounded the corner of the final stretch, the crowd went absolutely wild. (To be honest, I might have, too, if I was in the stadium.) LOOK HOW FAST SHE WAS RUNNING. What’s more, Kaylyn’s incredible burst helped Team USA land a new world record— during a preliminary heat. Incredible stuff. Well done, Kaylyn and crew.