How to Do a Crunch Correctly (So You Can Finally Stop Wondering)

two people on exercise mats in a Planet Fitness gym
Ahhh ... the elusive abdominal crunch. Once you learn how to do a crunch correctly, you can perform them anywhere there's enough space.

Ahhh ... the elusive abdominal crunch. Side crunch, machine crunch, reverse crunch — it's easy to get lost trying to decide what exercise to do, but let's take a step back and focus on how to do a crunch correctly so that you're always in the right form, no matter which you choose!

If you can learn how to do a crunch correctly, then you can perform these anywhere you can find a little bit of space. And the benefit doesn't stop with the crunch; learning how to move your body safely and with the correct form will allow you to transfer this knowledge to a whole range of other exercises.

Follow these five steps to perform an abdominal crunch properly.

1. Find Your Starting Position

Lie on the floor with bent knees. Keep your knees in line with your toes — don't allow them to cave inward. Place your fingertips on either side of the back of your head and stretch your elbows out wide — don't hold onto your head, as this increases the chances of you pulling on your neck. Alternatively, you can cross your arms over your chest, or stretch them out to either side of your thighs. Keep your feet flat on the floor throughout the movement.

2. Brace Your Core

Once in your starting position, take a deep breath and hold it. Imagine that you're wearing a belt, then tilt your hips to point the belt buckle up toward your belly button; you should feel your stomach muscles tighten when you do this. Now, take a short exhalation (as if you're 'shushing' someone) to pull your ribs down toward the floor. You now have a braced core (and should definitely be feeling it!). Try to maintain this position throughout the exercise to both protect the spine and make the exercise more effective.

3. It's Crunch Time

Now you're ready to crunch! This exercise is all about control and doesn't require much movement at all. All you need to do from here is imagine you're trying to draw the top of your stomach muscles closer to your belly button. The movement of your spine occurs at your mid-to-upper back and your neck should remain in a neutral position. When performed correctly, only your shoulders should come off the floor. Control the movement in both directions — don't relax on the way back down.

4. All About the Breath

Performing this exercise correctly isn't just about the movement. You need to make sure that you're using your breath correctly to get the most out of this exercise — a key component of exercise that translates to all other activities. On the upward phase of the crunch, you should exhale, in the same 'shushing' action as when bracing your core. You will automatically inhale as you return to the start position. Don't rush this exercise — between each repetition, make sure that you've returned to the start position and that your core is braced as described above.

5. Performance & Progress

Perform 2-3 sets of 10-15 repetitions. Try to progress by adding a repetition or two each session. Once you have progressed to the point where you are able to perform 25 repetitions in all of your sets, you can make the exercise more difficult by adding a one to three-second hold at the top of the movement in each repetition.

So there you have it. Now you know how to do a crunch correctly. Remember, not everything you see in the gym or on YouTube is correct; so, if in doubt, ask a professional — don't just copy the person next to you!

As always, please consult with a physician prior to beginning any exercise program. See full medical disclaimer here.