Many professional athletes, regardless of gender, wear what's known as a GPS tracking vest, which often gets mistaken for a sports bra. These vests hold a GPS device that tracks their performance, movement, and physical stats during the game.
When I first noticed players wearing these, I thought they were sports bras, too, and it seemed odd. I wasn't a fan, thinking they'd be uncomfortable and not worth the hassle. However, that was before I tried a well-made one. The comfort level changed my mind entirely, and you can even get a
custom sports bra that lets you choose everything from the fit to the fabric.