Forget what your fifth-grade gym teacher told you. Full sit-ups – where you lift your torso all the way up so your elbows touch your bent knees – are "way outdated," says Renderer. Crunches are much more effective. "You just need to curl your trunk so you're raising your shoulder blades off the ground," Bryant says. "The rectus abdominis muscle has a short range of motion, so all that extra movement in a sit-up doesn't engage it any further. Crunches focus contraction where it is most maximized."
Credit: Getty Images
Powered By ZergNet
The Adventure Issue
Eight Trips That Take Your Further
Plus: The Toughest Agent in the NFL
ON NEWSSTANDS NOW
Cesar Millan's Life Advice
Sign up to receive the Men’s Journal newsletter and special offers from MJ and its marketing partners.