Work Your Abs in Just 15 Minutes

Move 4: Bicycle

Lie on your back with fingertips behind ears, legs in the air, and knees pulled toward chest (top illustration). Target your sides and entire ab area by contracting as you lift your shoulder blades off the ground. Straighten your right leg at a 45-degree angle and rotate your upper body to the left, bringing the right elbow toward the left knee (bottom illustration). Switch sides by straightening your left leg, bending your right leg, and bringing the left elbow to the right knee. Alternate sides in a pedaling motion. Complete 8 to 12 full reps.