Ladies—make sure you’re supported in the bra department.
This took me a while to figure out, as even not-well-endowed women get the painful bounce. Since I’m sure your goal is not to put on a show while you workout, drop some cash on a decent sports bra.
I recommend the Fiona bra or the Enell if you’re larger on top. If you’re not, you can probably make due with a department store kind that’s fitted well. Can’t afford to buy a new one? One trick I’ve used is to wear two. Sure, it’s a little uncomfortable at first, but your chest will thank you.