While doing 100 crunches [1] won't diminish belly fat, once you dial in your diet and lower your body fat percentage, you'll want to reveal your strong, chiseled abs! These crunch variations are basic yet effective, and if you want defined abs, these ab-busting moves [2] will help make it happen!

V-Sits

• Lie on your back and reach your arms rigidly to your sides, off the floor. Lift your legs off the floor and point them so they are at about a 45-degree angle. Lift your head so your shoulders are off the floor as well.
• When you're ready to begin, lift your upper torso off the floor and bend your knees. You can lean back to make this move harder or come up more to make it easier. Slowly lower your upper body back down to the floor, straightening out your legs as you do so. Stop when your back is on the floor, but not your head, shoulders, or legs.
• This completes one rep.

Crunchy Frog

• Begin sitting, balanced just behind your sits bones, and rock back slightly to lift your feet off the floor; gently pull your knees to your chest.
• Exhale, pull your navel to your spine, and lean back slightly as you open your arms to the sides and straighten your legs.
• Inhale and return to the starting position to complete one rep.

Butterfly Crunch

• Lie on your back with your knees open and the soles of your feet together (in a butterfly position). Lengthen your arms overhead so they are resting on the floor.
• Exhale and bring your hands and knees toward each other, performing a full-body crunch. Your shoulder blades should be off the mat as you perform a small reverse crunch, lifting your pelvis a bit off the mat. Hold this position for a moment, and really feel your abs squeezing.
• Slowly lower your arms and feet back to starting position to complete one rep.

Diamond Sit-Up

• Lie on your back and open your legs into a diamond shape (aka butterfly legs) with the soles of your feet pressed together and knees out wide. Extend the arms overhead.
• Inhale to curl the torso up and tap the floor in front of your feet to stretch your glutes a bit.
• Slowly lower back to the starting position.
• This counts as one rep.

Reverse Crunch

• Lying on your back, lift your legs in the air with your knees bent. Place your hands on the floor beside you.
• Without momentum, use your lower abs to slowly curl the hips off the floor and into your chest. Slowly lower them back to the starting position.
• This counts as one rep.

Half Banana

• Start lying on your back with your arms reaching toward the ceiling.
• Exhale and roll up toward sitting while lifting your left leg up. Pause at the top and reach for your toes before rolling down slowly back to the mat, then perform on the other side. This completes one rep.

T-Cross Sit-Up

• Begin lying on the floor with your arms out wide to the sides, making a T with your body.
• Sit up, lifting your right leg, and twist to bring your left hand to your right toes. Slowly roll back down, and repeat on the other side.
• This completes one rep.

Straight-Leg Sit-Up

• Begin on your back with your legs straight and arms raised toward the ceiling.
• Roll up to sitting, focusing on the abs rounding the back. Roll back down to the mat slowly, one vertebra at a time.
• This completes one rep.

Runner's Crunch

• Start on your back with your elbows resting on the floor at a 90-degree angle.
• With your core engaged, roll up to almost sitting while bringing your right knee up to meet your left elbow. It should feel a little like running.
• With control, straighten your leg as you slowly lean your back down, vertebra by vertebra, until your shoulders touch the mat last.
• Alternate with your other leg to complete one rep.

Pilates Roll-Down

• Begin seated at the front edge of your mat, with knees bent and legs parallel. Reach your arms toward the ceiling to lengthen your spine.
• Exhale and pull abs deeply toward spine, and begin to roll down the floor one vertebra at a time; the movement should be smooth and controlled. Once your head reaches the mat, reach your arms overhead so they are parallel to the floor.
• Exhale and begin to roll up, peeling your spine off the mat and coming all the way to sitting. Inhale your arms up toward the ceiling. This completes one rep.

Ab Curl

• Start sitting and place a ball at your low ribs. Then lean back, so your torso is almost parallel to the floor. Place your hands behind your head, keeping your elbows wide.
• Exhale, pulling your abs to your spine while pressing the low ribs into the ball to perform a curl. The movement is small but concentrated.
• Inhale, and lower your chest without arching your back to complete the rep.

V Crunch

• Lie on your back and lift your legs and arms up so they are extended toward the ceiling. Lift your upper back off the floor, reaching your hands toward your feet.
• Lower your legs toward the floor while reaching your arms overhead, keeping your shoulders off the mat and your lower back pressed into the mat.
• Repeat the crunch motion to complete one rep.

Bicycle Crunches

• Lie flat on the floor with your lower back pressed to the ground (pull your abs down to also target your deep abs). Interlace your fingers and put your hands behind your head.
• Bring your knees in toward your chest and lift your shoulder blades off the ground.
• Straighten your right leg out to about a 45-degree angle to the ground while turning your upper body to the left, bringing your right elbow toward the left knee. Make sure your rib cage is moving and not just your elbows.
• Now switch sides, and do the same motion on the other side to complete one rep (and to create the "pedaling" motion).

Oblique V-Crunch

• Lie on your right side with your left hand behind your head and right hand on the floor.
• Press down into your right hand as you raise your straight legs off the floor, bringing your torso toward your legs.
• Lower yourself back to the floor with control. This completes one rep.

Scissor Abs

• Lie flat on your back. Extend your arms so they're against the sides of your body with your palms pressing into the floor, or bend your elbows and place your palms under the back of your head. Bend your knees and draw them into your ribs. This will make it easier to pull your navel in toward your spine and actively press your lower back flat on the ground.
• Lift both legs straight up toward the ceiling, continuing to engage your abs and pressing your lower back into the ground. Keeping your core strong, slowly lower your right leg down toward the ground until it is a few inches above.
• Then slowly scissor your legs, lifting your right leg back up as you lower your left leg down toward the ground. This completes one rep.

Double Crunch Pulse With Medicine Ball

• Begin lying on your back with your legs in the air, toes toward the ceiling, holding the medicine ball over your chest with straight arms. Engage your abs to press your low back into the mat while lifting your head, neck, and upper back off the mat.
• Exhale and round your low back so the bottom of the pelvis raises as you lift your upper body an inch higher off the mat. Aim the medicine ball toward your ankles as you perform this double crunch.
• Inhale, and lower the pelvis and upper back an inch toward the floor. Continue this slow pulsing motion.

Dumbbell Crossover Punch

• Begin by lying on your back with your knees bent and your feet flat on the ground, about two feet from your butt. Hold weights, five- to eight-pound dumbbells, in both hands at your chest with your elbows on the floor.
• Keeping your hands at your chest, roll up to a sitting position. Twist your ribs to the left as you "punch" your right hand to the outside of the left knee.
• Bring the right hand back to your chest as you untwist, bringing your torso back to the centre, and roll down to the ground.
• Repeat the sit-up, twisting to the right side to complete one rep.

Coordination Fly

• Lie on your back with a three- to five-pound dumbbell in each hand. Raise your arms straight up above your chest, with a slight bend at each elbow. Raise your legs up to tabletop, with knees and hips bent to 90-degree angles.
• Inhale and open your arms to your side, with a slight bend at each elbow. Exhale as you bring your arms back up to starting position.
• Once your arms are back straight, lift your upper back and curl up toward your legs, pushing your weights toward your shins. As you curl up, stretch your legs out in front of you.
• Uncurl your spine slowly as you lower your upper body to the floor while bending your knees back to 90-degree angles. Once your head is back on the floor, release your arms to back out by your side, making sure not to let your upper arms touch the floor.

Crunches on Exercise Ball

• Sit on a well-inflated exercise ball.
• Place your hands behind your head and walk your feet away from the ball so your torso starts to roll onto the ball. The ball should support your hips and the curve of your lower back. Your legs should form a bridge with your knees bent at right angles.
• Exhale and lift your upper body by about 45 degrees, pulling the deep abs in toward the spine, and return to starting position. Don't yank your neck!

Upper-Ab Crunch

• Lie on your back with your feet together and knees opened in a butterfly position.
• Place the ball at the bottom of your shoulder blades and then place your hands behind your head.
• Exhale, pulling your abs to your spine, and contract your upper abs as you perform a crunch. Continue this motion with small, concentrated pulses.