REVERSE CURL
Lie faceup, knees bent, heels close to your buttocks and fingertips behind head [A].

 

 

Without changing knee angle, contract abs to curl your tailbone a few inches off the floor, knees rolling toward chest [B]. Avoid moving thighs to lift higher; keep heels toward buttocks. Slowly lower to floor; repeat for all reps. Begin with 8–12 reps; gradually build to 16–20 reps. Targets rectus abdominis and obliques.