>>76816054
Roidgutted bodybuilders like Nick Walker train them in the hopes that it will make their waist thinner or give them better "waist control" while they're on stage, even if they don't actually attempt to pull vacuums there. Obviously if it works it's only marginal since they all still look pregnant between poses. It's like pullovers to expand your ribcage, wide grip pulldowns to make your lats wider or calf raises. If you're competitive you have to do them just in case. For normal people, if you enjoy them do them, if you don't don't.