Ab Crunches: Proper Form, Variations, and Common Mistakes

Crunches have been the mainstay of ab workouts for decades. They target the rectus abdominis, the six-pack muscle that runs along the front of the torso. Ab crunches can be part of core strength or total-body workouts.

How to Do Abdominal Crunches

Lie on the floor and bend your knees, placing your hands behind your head or across your chest. Some find crossing arms over the chest helps avoid pulling on the neck.

1. Engage your core.
2. Crunch your ribs toward your pelvis using your abdominal muscles.
3. Exhale as you come up and keep your neck straight, chin up.
4. Hold at the top of the movement for a few seconds, breathing continuously.
5. Lower slowly down, but don't relax all the way.
6. Repeat for 15 to 20 repetitions with perfect form for each rep.

Benefits of Ab Crunches

Ab crunches work the muscles on the front of your abdomen called the rectus abdominus, also known as the six-pack. The rectus abdominis muscle flexes to bring your shoulders toward your hips.

As one of the major core muscles, it provides stability for your body. A strong back and abs are the foundation of your daily movements and sports performance. A strong core is imperative for preventing back pain and strain and promoting spinal and pelvic stability.

Abdominal Crunch Variations

Perform ab crunches in different ways to meet your skill level and goals.

Full Ab Crunches

1. Lie on your back and engage your core. 
2. Bring your shoulders 1 or 2 inches off the floor imagining you are bringing your ribs toward your pelvis. Bring your knees in at the same time you lift your upper body.
3. Exhale as you come up and keep your neck straight, chin up.
4. Hold at the top of the movement for a few seconds, breathing continuously.
5. Lower slowly back down without fully relaxing.
6. Repeat for 15 to 20 repetitions with perfect form for each rep.

Exercise Ball Crunch

1. Place your upper to mid-back on an exercise ball with your feet flat on the floor.
2. Engage your abs and crunch your ribs toward your pelvis using your abdominal muscles.
3. Hold the crunch at the top for a count before slowly lowering down over the ball.
   

Ab Crunches: Common Mistakes

Performing ab crunches correctly is more complex than it looks. Avoid these errors so they can be as effective as possible.

Pulling on Your Neck

This not only strains the neck, but it takes away from working your abs. Originate the movement in your abs, not from your head. Place your fist under your chin to keep your neck in proper alignment during ab crunches.

Crunching Too High

The ab crunch is a subtle movement that lifts the shoulder blades a few inches off the floor. Jerking the shoulders up adds momentum and reduces the effectiveness of the exercise. It takes time to build strength in the abs, so take your time and complete the move slowly rather than using momentum to lift your body.

Relaxing Down to the Floor

It's easy to let your shoulders fall to the floor during ab crunches, but a more effective approach is to keep tension on the core throughout the movement. You never want to relax your shoulders onto the floor completely.

Back Arch

In the past, it was recommended to keep your back flat against the floor throughout the entire movement. Now it is believed it is better to keep a neutral spine, meaning your spine is in the strongest position to support you.

A quick way to find it is to rock the pelvis back and then forward and then allow your pelvis to relax somewhere between those two extremes. If your back arches too much, your abs may need time to build strength. Try propping your feet on a step or platform to support your back during ab crunches.

Safety and Precautions

If you have back or neck problems, talk to your doctor or physical therapist about whether abdominal crunches are appropriate. If not done with proper form, they can compress the spine and stress the neck. You may need to avoid ab crunches after the first trimester of pregnancy and postpartum if you have diastasis recti. Speak to your healthcare provider for more information.

Try Ab Crunches

Incorporate ab crunches into one of these popular workouts:

• Ab Exercises for Athletes
• 20-Minute Core Workout
• Intermediate Ab Workout