Build strong core muscles without weights, just using these three crunch variations from a functional training coach.

The crunch clapping exercise is exactly as it sounds ... but the most popular starting positions involve sitting in a v-sit position or laying on your back; you’ll then raise your legs ...

The crunches vs sit ups debate can leave many of us confused. What’s the difference between these two ab-building moves, which is best for your personal fitness goals, and what are the pros and cons ...