How to Do Crunches Properly

This popular variation works your rectus abdominis and external obliques, predominantly in the lower abdominal region.

1. Lie down on the floor with knees bent and feet planted hip-width apart.
2. Place your hands on the floor by your side.
3. Inhale, contract your abs toward your spine.
4. Exhale and lift your feet off the floor and raise your knees upward and inward toward your chest, keeping your knees at a 90 degree angle. Your hips should tilt inward to crunch your abs.
5. Slowly lower your feet to the floor.

A bicycle crunch fires up your transversus abdominis, the deepest of the abdominal muscles. This is considered one of the key muscles to prevent back pain.

1. Lie down on the floor with knees bent and feet planted hip-width apart.
2. Place your hands gently on your head with elbows out wide, with fingers grazing your ears.
3. Lift one leg off the ground and straighten it outward, raising the opposite knee upward toward your chest.
4. Lift your chest upward and turn your torso — opposite elbow to opposite knee.
5. Lower back to a neutral position with knees raised.
6. Switch to the other side — opposite elbow and opposite knee.

A medicine ball variation can increase the intensity of a traditional crunch and fire up your obliques.

1. Sit on the floor and raise your feet off the floor. Straighten your legs with a slight bend in the knee.
2. Hold your medicine ball in front of your hips and lean back to a 45 degree angle.
3. Move the ball from the left-right, twisting your torso and contracting your obliques.

The slower and more controlled you perform crunches, the better ab activation you’ll get. That’s because you’re increasing the time under tension. A single crunch should last a few seconds, performed in a controlled manner. Aim for around two second in the concentric phase (when you lift shoulders up) and two seconds in the eccentric phase (when you lower).

A common complaint from crunches is neck pain. This is a sign you’re not practicing proper form. Avoid neck pain by keeping your gaze ahead and neutral and tucking your chin toward your chest. This position reduces the activation of the hyoid muscles, which are the stabilizing muscles that run from your chin to your collarbone. You want to be putting the responsibility of stabilization back into the abdominals.

Remember, crunches are not sit-ups! You don’t want to lift your entire upper body when coming up. This is a small movement. In fact, the smaller the movement, the more difficult it becomes as you don’t build up momentum. Aim to raise your shoulder blades just a few inches from the ground.

The concentric phase of a crunch has two parts: you want to curl and lift your shoulders from the ground to come up. If you just curl your shoulders, you’re not getting the elevation and you won’t target your abdomen fully. If you struggle to feel the burn when you crunch, this might be your issue. Visualize bringing your ribs to your pelvis on the exhale as you curl and lift upward.

Here’s the truth: Your arms have nothing to do with crunches. Crunches are an abdominal isolation exercise. Your arms can be in any position you choose — whether that’s across your body, out to the side or tilting inward. Choose a position that is comfortable for you and that allows you to focus on the mind-muscle connection with your abs, not your arms.