The popular abdominal exercise known as the "crunch" is actually bad for you because it puts a tremendous strain on the spine and promotes the hunched-back posture. Here are some safe, ab-strengthening exercises from golf's top's fitness experts.
Lie on your side with your elbow under your shoulder, feet stacked. Using your forearm, push your hip off the ground. Keep your head in line with your spine. Hold. Strengthens shoulders, abs, obliques.