Work Your Abs in Just 15 Minutes
Turn onto your right side with your legs extended and your feet and hips resting on the ground and stacked on top of each other (top illustration). Place your right elbow directly under your shoulder to prop up your torso, and align your head with your spine. Gently contract your core and lift your hips and knees off the floor; this strengthens your sides and deep ab muscles (bottom illustration). Hold for 10 to 30 seconds, gradually working up to a minute, and return to the starting position. Roll onto the other side and repeat.