On your quest for perfect abs, don't forget your supporting cast. Your obliques are actually two sets of muscles -- the internal and external obliques -- that run along the sides of your torso from your ribs to your pelvis. These muscles keep your torso stable and upright, and allow you to rotate your upper body. This is why many exercises that build the obliques involve twisting or side-to-side motions. When they're tight and toned, they suck in the gut like a corset to give both men and women an enviably narrow waist, minus the love handles and muffin tops.
Warm up your obliques and prevent injury with the torso twist, a dynamic stretch. Stand with feet slightly greater than hip-width apart. Lift your arms until they're level with your chest and bend your elbows 90 degrees. Without moving your legs, rotate your upper body to the right and then to left in a fluid motion. Concentrate all of your movement in your torso and keep your back straight. Perform 10 to 20 stretches on each side.
Lie on your mat on your left side to begin side crunches. Stack your right foot on top of your left. Place your right hand on the back of your head and bring your left arm around your torso. Rest your left hand on your right side obliques -- this will help you feel them working. Tighten your obliques to lift your head and shoulders sideways off the mat. Lower and repeat for one to three sets of 10 to 12. For an extra challenge, hold your last rep on each side for 15 to 45 seconds.
Lie on your back, knees bent and feet flat on the floor, with a medium-weight dumbbell or medicine ball in your hands, to begin Russian twists. Tighten your torso to lift your head and shoulders off the mat. Rotate your torso to the right and bring your weight to the mat on your right-hand side. The twisting motion helps target your obliques. Hold for five seconds, then rotate your torso and weight to the left. Perform 10 repetitions. This exercise also works your arms, shoulders and chest. For an additional challenge, set an ab bench to 45 degrees and lie on it so that your body is at an incline and your knees are hooked over the edge of the bench. In this position, you'll be lifting your upper body weight and twisting against gravity.
Lie on your back, and lift your feet straight into the air to perform toe-touch crunches. Tighten your core and lift your head and shoulders off the mat as you reach toward your left toe with your right hand. Lower your shoulders back to the mat and repeat, this time reaching toward your right toe with your left hand. Continue for three sets of 10 to 12 repetitions on each side.
Stand with feet slightly wider than hip-width apart and hold a medium dumbbell in your left hand to perform weighted side bends. Place your right hand on your hip or on the side of your head and bend your upper body to the right. Keep your back straight and bend until you feel tension, but not pain, in your left oblique muscle. Return to start and continue for 10 to 12 repetitions on each side. Perform two to three sets on each side.
Stand feet hip-width apart with a medium-weight dumbbell or a medicine ball in your hands in front of you to perform woodchoppers. Twist your upper body to the right, lifting your weight upward toward your right shoulder, as though you're lifting an ax to chop wood. Keep your back straight. Hold for one second and return to start, then repeat on the left side. Perform one set of 10 to 15 repetitions on each side. This exercise works your arms and shoulders along with your obliques.
Climb onto your captain's chair with your feet hanging straight down, back flat against the back of the chair and your forearms comfortably planted on the arm rests to perform twisting knee raises. Bend your knees at a 90-degree angle and tighten your left-side obliques to lift your left hip up toward your left elbow. Return to start and repeat with the right oblique and right hip. Perform two to three sets of 10 to 12 repetitions on each side.
Stretch your obliques and cool down with a side bend. Stand with feet slightly wider than hip-width apart. Place your right hand on your left-side obliques and stretch your left arm over your head. Bend your torso to the right, reaching over your head with your left hand, to stretch your left-side obliques. Hold for one minute, then repeat with your right-side obliques.
Eat at least 60 grams of lean protein a day in the form of fish, chicken, lean red meat, nuts, legumes and/or soy products to help you build muscle. About 30 percent of your daily calories should come from protein.