Lie on your back with your hands behind your head. Raise your legs so your knees are bent at a 90-degree angle; keep your feet flat and toes pointed toward the ceiling.
Perform three crunches, making sure not to pull on your neck as you lift your back off the floor.
With your legs still bent at a 90-degree angle, drop your arms down to your sides, palms touching the ground.
Perform three reverse crunches, using your lower abs to slowly curl your hips off the floor and into your chest, then back down to the mat.