How to Do Crunches So They Actually Work Your Abs

This advanced crunch variation can be a little hard on your hip flexors and lower back; if you experience any pain, stop doing this exercise and rest or try a different move.

• Start seated on the ground with your feet on the floor in front of you, knees bent. Place your hands about an inch behind your back with your fingers facing forward. Lift both feet up off of the ground, and balance on your glutes.
• Extend both legs to hover just off the floor as you simultaneously lower your upper body a few inches.
• Using your abs, bring your legs back to your chest. That's one rep.