10 Fat Burning Ab Exercises

9. Side Plank

This challenging variation of the plank also requires an absolutely straight body in a test of strength and stamina—only you're targeting your obliques. Lie on your left side and place your left forearm flat on the floor. Raise your hips until your body forms a straight line and engage your abs. When you feel stable, lift your right arm straight up in the air. Hold for 20 seconds—or longer if you can—increasing the time each week until you can hold for one minute. Repeat on the right side.