The Reverse Crunch is the opposite movement of a Sit-up, which means: we will approach our pelvis to our breastbone contracting the abdominal muscles. This exercise strengthens your abs and causes less strain on your back and neck than a regular crunch.
Lie on your back and extend your arms out to the side. Raise your knees and feet so they create a 90-degree angle.
Exhale and contract your abs lifting your hips off the floor with control; your knees will move toward your head. Try to keep your knees at a right angle.
Inhale and slowly return to starting position. Don´t swing your legs up and down. Focus on your abs and try to lift your hips off the ground.