In fact, Liu offers this detailed for how to do them: 'Position yourself either hanging from a pullup bar or on a roman chair with your lower back pressed against the pad,' he says. 'Crunches and sit-ups focus on the upper abs, whereas hanging leg raises work the entire abdominal area, accelerating muscle gain.' 'They're great for building your abs and it's one of the best exercises you can do for them,' says Tim Liu, C.S.C.S., ETNT Mind+Body's resident training guru. He's not the only trainer that says the hanging leg raise is top among abs exercises for a six-pack.
