Why Bicycle Crunches Can Be Bad for Your Back (With Fixes)

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A man holding his lower back in pain while doing bicycle crunches.
Eric performs bicycle crunches with his back arched, which is causing back pain.

I asked 59 people if bicycle crunches give them lower back pain. 14 of them said every time, while almost half said sometimes. Maybe this exercise is just bad for your back, or maybe it comes down to form inconsistency and bleed-over fatigue.

Bicycle crunches are not inherently bad for your back as long as you’re breathing properly and maintaining a rounded lower back. However, performing the twisting and crunching motions with an arched back will lead to overactive hip flexors causing lower back compression.

You may have heard horror stories about people injuring their backs during bicycle crunches. Below I’ll discuss why they can hurt your back and how to prevent it from happening.

Why Bicycle Crunches Can Be Bad for Your Back

Maintaining a flat or arched lower back is safe when performing strength training exercises such as squats and deadlifts. The vertical weighted pressure keeps the spinal discs in line using the deep transverse abdominis (ab muscles).

Conversely, bicycle crunches, target the rectus abdominis and obliques, which are the easy-to-see six-pack ab muscles. These two muscles are most engaged during exercises that twist the torso and round the spine such as in bicycle crunches.

If they’re not properly engaged, bicycle crunches may hurt your lower back for various reasons:

  • Using your psoas muscles (hip flexors): Failing to round the lower back causes the psoas muscles to arch the spine.
    • With a lack of vertical pressure from gravity, this arched position pushes the intervertebral discs forward, causing back pain and joint compression.
  • Twisting with an arched back: Arching your back during crunches does not target the abs.
    • When the crunching and twisting components are combined with an arched back, this causes the deep vertebral and superficial spinal erector muscles to cramp.
  • Your deep back muscles may also just be over-fatigued: Heavy exercises can fatigue the lower back, regardless of whether you use proper form or not.
    • A sore back from deadlifts or squats may have bleed-over effects, impeding your performance on bicycle crunches.

Twist with your abs and press your lower back against the floor when performing bicycle crunches to avoid these back-related pain symptoms. Below are some cues to help.

How To Avoid Hurting Your Back During Bicycle Crunches

Trainees often do bicycle crunches by focusing on bringing their elbows to their knees. They pay no attention to actively engaging their abs throughout the motion and end up hurting their back.

When performing bicycle crunches, exhale to round your lower spine against the floor while twisting. Also, loosely touch your fingers to your ears and keep your upper back off the floor. This ensures the rectus abdominis and obliques work instead of the back or hip flexors.

Failing to keep your lower spine rounded against the floor while twisting can cause the deep nerves and muscles around the back to compress and cramp.

Here’s a closer look at the does and don’ts to protect your back when performing bicycle crunches:

DoDo Not
Flair Your elbows Tuck your elbows in front of your face
Lightly touch your fingers to your earsPress your hands against the sides of your head
Round your upper back to keep it from touching the floorTouch your upper back to the floor between reps
Press your lower back into the floorLift or arch your lower back off the floor
Exhale and squeeze your abs to twistHold your breath, twist your neck, or use leg momentum
Point the toes of the extending leg forwardFlex the ankle of the extending leg
Slowly guide the bending of the leg through your kneeJerk the bending leg toward your chest
End the set once your abs can no longer perform the twistsTry forcing reps by using momentum

1. Lightly Touch Your Fingers to Your Ears

Barely touching your ears prevents your hands from pushing your head and tweaking your upper spine when twisting. It also helps to flare your elbows out so they’re aligned above your shoulder blades.

2. Keep Your Upper Back Rounded and off the Floor

Rounding your upper back and holding this position helps keep constant tension on your abs.

On the other hand, resting your shoulder blades on the floor between reps will disengage your rectus abdominis and obliques. Your back muscles will have to work harder to continuously move from the arched to the rounded position.

3. Keep Your Lower Back Pressed Against the floor

Not pressing your lower back against the floor makes arching your back more likely, disengaging the abs and increasing the chance of back pain.

Also, avoid lifting your lower back off the ground when twisting forward, even if it’s still rounded, as the quads and psoas will become more involved.

4. Exhale and Squeeze Your Abs While Twisting

I’ve found exhaling while performing each rep makes keeping my lower back pressed against the ground much easier. Conversely, your back will automatically want to arch if your stomach is filled with too much air.

5. Extend One Leg With the Toes Pointed Forward

Pointing your toes forward helps relax your leg muscles and puts the abs in charge of holding their dead weight.

6. Drive Through Your Knee To Bend the Other Leg

When raising your leg toward your chest, guide the movement through your knee. I find this helps keep my quads and hip flexors more relaxed.

7. Stop Once Your Abs Reach Muscular Failure

Because bicycle crunches are a bodyweight exercise, they are often performed for high reps. Regardless, don’t get carried away with hitting a certain rep target.

If you start resting your shoulder blades on the ground between reps or notice your legs are contributing more than your abs, end the set.

Avoid absolute failure. Work until muscular failure.

For example, instead of cranking out 50 reps in a single set, do as many of those reps as you can with good form. Then, take a 30-second break and repeat this process until you hit 50 total reps.

If Bicycle Crunches Hurt Your Back, Try Wall Sits

In some cases, you may not have the abdominal control to perform bicycle crunches yet as they’re fairly complex. Or maybe your back is sore from a heavy deadlift session you did last week.

Either way, isometric exercises like the wall sit help develop a mind-to-muscle connection with your rectus abdominis by focusing on keeping your lower back rounded against the wall while taking deep exhales. You won’t have to worry about twisting too fast and potentially hurting your back.

Eric De Cremer
Eric De Cremer

Eric is an NCCA-accredited Certified Personal Trainer and competitively trained powerlifter. Feel free to contact him anytime at edecremer@wildnswole.com!