I use this cup during Brazilian Jiu-Jitsu practice every week, and it's worked out great. It's comfortable, stays in place, fits well, and protects me from errant knees to the groin. While training, I honestly forget that I have this supporter on - which is a great sign, and has definitely not been the case for me in the past.

I usually wear a 32 waist, bought the medium size, and was a little surprised at how tight the waistband was. I would definitely say that this product seems to run tight, so if you're on the fence about which size to order definitely keep this in mind.