Crunch Exercise: How to Do It, According to an Expert

Crunches are a classic core-strengthening exercise. Whether you’re a frequent gym-goer or a fan of home workouts, there’s a good chance you’ve already come across them before. Considering that crunches are one of the first exercises many of us learn about early in life (the dreaded Presidential Fitness Test comes to mind), knowing how to do crunches correctly might seem like a bit of a no-brainer. But the reality is that many people still aren’t getting the most out of their crunches. Thankfully, experts are here to help.

Like all exercises, crunches work best when they’re done with proper form. To walk us through the basics, we spoke with Grace Taylor, PT, DPT at H&D Physical Therapy, and gathered insight about this timeless core move. Read on to find out how to do crunches correctly, and whether or not this ab exercise is actually worth your time. Plus, amp up your next ab workout with 11 crunch exercise variations that work your abs in different ways.

Crunch Exercise Benefits

Crunches utilize and strengthen your rectus abdominis (the ab muscle along the front of your stomach), internal and external obliques (which wrap around the sides of your stomach), transverse abdominis (your deepest, corset-like ab muscle), and hip flexors, Taylor says. The muscles utilized during crunches are important stabilizing muscles in the body. Better stability means better balance, lifting, postural control, and power production, plus minimized aches and pains, particularly in the lower back. Overall, a strong core supports just about every movement you do.

And the crunch movement does show up in your everyday life — think about how you get out of bed in the morning or get up from a couch or lying on the floor. Strengthening the muscles involved in this movement pattern will help you continue to execute it safely in your day-to-day.

Crunches Form Tips

There are two common positions for your hands while performing crunches, and Taylor has a preference. You can either place your hands behind your head, or you can cross your arms over your chest.Placing your hands behind your head creates a longer lever arm and requires more intense core work. However, with this added challenge, it’s easier to use momentum, rather than strength, to complete your crunches. This can place a lot of pressure on the spinal segments in the neck and upper back. If you use this variation, ensure your arms remain inactive throughout the entire exercise, so you’re not pulling on your neck. Placing your hands on your chest makes it easier to round your midback during the crunch, which can place more pressure on your spine and decrease your core use. However, this position is less likely to strain your spine than placing your hands behind your head, which is why Taylor recommends it.

To keep good form, Taylor recommends that you avoid tucking your chin toward your chest. A good way to avoid this is by finding a spot on the ceiling to keep your eyes on. Additionally, making sure you keep your low back flush with the ground is key. Sitting up too much can put a lot of strain on your spine and hips — if your back comes off the ground, know that you’ve gone too far. (That move is generally considered a “sit-up” rather than a crunch.)

Oftentimes when crunches are done absentmindedly, your hip flexors take over and pull on your lower-back muscles, which may cause spinal issues down the road, says Glo coach and trainer Ridge Davis. When the hip flexors do too much work, they disengage your abs, making the crunch exercise far less effective as a core move. “It’s all about awareness when performing crunches — or any exercise for that matter,” Ridge says.

How to Do Crunches

With these tips in mind, it’s worth learning how to do crunches correctly. “My philosophy is that there is not a bad exercise but a poorly executed one,” Davis says. To learn the right technique, follow these specific steps.

Crunch Exercise Modifications

Taylor confirms that crunches are a heavily debated exercise. Like burpees, they can be beneficial if done property, but they can also put a lot of strain on your spine. Taylor doesn’t recommend crunches to people with a history of neck or back pain and recommends choosing a different core exercise if you have pain during, immediately after, or the day after you do crunches. The good news? We have some ideas for you right here.

Keep reading for some crunch exercise variations that target different parts of your core and can be better choices depending on your exercise history and ability.