If You Can Do This Many Sit-Ups in 60 Seconds, You're in Great Shape
A trainer explains how many sit-ups you should be able to do in 60 seconds to signal peak fitness and how to boost your ...
You'll never do sit-ups again after trying these 5 dumbbell ab exercises — according to a personal trainer
The sit-up is still programmed, but many other exercises can strengthen your core muscles just as well, if not better. It’s a ...