The crunch is a classic core exercise. It specifically trains your abdominal muscles, which are part of your core.
Your core consists not only of your abs. It also includes your oblique muscles on the sides of your trunk, as well as the muscles in your pelvis, lower back, and hips. Together, these muscles help stabilize your body.
While the crunch is a popular core move, it isn’t safe for everyone. It can place a lot of stress on your back and neck, and it only works your abs, not the other muscles in your core.
In this article, we’ll look at the pros and cons of doing crunches, and how to do the exercise with good form. We’ll also explore alternative exercises that may be safer and more effective at working your core muscles.
While the crunch has many benefits, it also has some disadvantages. It’s important to consider these factors before trying this move.
- Isolates the abs. Crunches exclusively work the abs. This is helpful if you’re trying to get a six-pack.
- Can be done without gym equipment. As a bodyweight exercise, the crunch can be done anywhere.
- Beginner-friendly. In general, crunches are ideal for most beginners.
- Only targets the abs. The crunch doesn’t engage the obliques or other core muscles, so it may not be the best exercise if you’re looking to strengthen your entire core.
- Risk for back and neck injuries. Your spine flexes during crunches. This may put strain on your back and neck, and increase the risk of injury in these areas.
- Potentially unsafe for older adults. Due to the flexing that’s required to do this exercise, it may not be safe for older adults, especially those who’ve had a back or neck injury.
The standard crunch is done on the floor. To make it more comfortable, you can do it on an exercise or yoga mat.
To do a crunch:
- Lie down on your back. Plant your feet on the floor, hip-width apart. Bend your knees and place your arms across your chest. Contract your abs and inhale.
- Exhale and lift your upper body, keeping your head and neck relaxed.
- Inhale and return to the starting position.
- Use your core to raise your upper body. If the movement comes from your head or neck, you’ll increase the risk for injury.
- Move in a slow, controlled manner. Rapid movements won’t engage the right muscles.
- You can place your hands behind your head, but this can strain your neck. It’s best to try this hand placement after you’ve mastered the proper form.
The bicycle crunch is an intermediate version of the basic crunch. It works both the abs and obliques.
To do a bicycle crunch:
- Lie down on your back. Bend your knees and plant your feet on the floor, hip-width apart. Place your arms behind your head, pointing your elbows outward.
- Brace your abs. Lift your knees to 90 degrees and raise your upper body. This is your starting position.
- Exhale and rotate your trunk, moving your right elbow and left knee toward each other. Simultaneously straighten your right leg. Pause.
- Inhale and return to starting position.
- Exhale. Move your left elbow to your right knee and extend your left leg. Pause. This completes 1 rep.
To avoid strain, keep your lower back on the floor and shoulders away from your ears. Rotate from your core instead of your neck or hips.
The following crunch variation is safer than traditional crunches. It works by supporting the lower back while keeping it in a neutral position. It also puts less strain on your upper back and neck.
To do a safer version of the crunch:
- Lie down on the floor. Bend your knees and plant your feet on the floor. Place your hands underneath your lower back and extend one leg.
- Contract your abs and inhale. Using your core, raise your head and neck a few inches off the floor, keeping your neck straight. Pause.
- Return to starting position.
The following exercises are safer alternatives to the crunch. They’re easier on the back and neck, which reduces the risk of strain or injury.
Plus, compared to crunches, these exercises work multiple muscles in the core instead of just the abs.
This beginner exercise is done in a similar position to crunches. But instead of moving your upper body, you move one leg at a time. This motion engages both your abs and pelvic muscles.
To do this exercise:
- Lie down on your back. Lift and bend your knees to 90 degrees. Brace your core and inhale.
- Exhale and tap your right toes on the floor, keeping your left knee at 90 degrees. Return to starting position.
- Repeat with the left foot.
The bird dog is an intermediate move. It targets your abs, as well as the muscles in your butt, hips, and back.
Also, the exercise is easy on your spine because it’s done on your hands and knees.
To do this exercise:
- Start on all fours. Place your hands shoulder-width apart and knees hip-width apart. Contract your core and inhale.
- Exhale. Straighten your right leg behind you, level with your hip. Simultaneously extend your left arm ahead, level with your shoulder. Pause.
- Repeat with the left leg and right arm.
The mountain climber engages your core, hips, and butt. It also trains your arms and thighs, making it a great full-body move.
Like the bird dog, it puts less stress on your back because it’s done on all fours.
To do this exercise:
- Start on all fours, hands shoulder-width apart and knees hip-width apart. Brace your core.
- Move your right thigh toward your chest and place your toes on the floor. Straighten your left leg behind you, flex your foot, and place it on the floor.
- Swiftly switch legs without moving your arms. Repeat.
This advanced exercise works your abs, obliques, and shoulders while challenging your balance. If you’re new to this move, try mastering the side plank first.
To do this exercise:
- Lie on the floor on your right side. Place your right elbow under your shoulder and put your left hand behind your neck. Align your head, spine, and legs.
- Contract your core. Lift your hips while keeping your body straight. Rotate your trunk, moving your left elbow to the floor. Return to starting position.
- After completing your desired number of reps, switch sides and repeat.
To make it easier, you can put your hip on the floor.
The crunch is often seen as the gold standard for ab exercises. However, it only targets the abdominal muscles, so it’s not a functional core workout.
Crunches can also be hard on your back and neck, so they may not be safe for everyone. Instead, you can try alternative exercises like the bird dog or mountain climber. Not only do these moves engage multiple core muscles, but they put less stress on your spine.
If you’d like to do crunches, consult a personal trainer. They can provide advice, modifications, and alternatives to keep you safe while also helping you get the best core workout.