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Bicycle Crunch: Technique, Muscles and Swaps

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Equipment
Bodyweight
Muscle group
Core
Main muscles
obliques, rectus abdominis
Also working
hip flexors
Mechanics
Compound
Pattern
Rotation + flexion
Level
Beginner

The bicycle crunch is a bodyweight core exercise that combines spinal flexion with rotation. You perform it lying on your back, bringing opposite elbows and knees together in a continuous pedaling motion. It requires no equipment and fits easily into any training session.

This compound movement targets the rectus abdominis and the obliques as primary movers. Your hip flexors also work as supporting muscles to lift your legs. By moving through rotation and flexion simultaneously, you build core coordination and control.

How to do it

Lie flat on your back on a mat with your knees bent and feet flat on the floor. Place your fingertips lightly behind your ears and keep your elbows wide.

  1. Lift your feet off the floor until your thighs are vertical and your shins are parallel to the ground.
  2. Engage your core to lift your head and shoulder blades slightly off the mat.
  3. Twist your torso to bring your right elbow toward your left knee while extending your right leg straight out.
  4. Pause briefly when your elbow and knee are close.
  5. Reverse the motion to bring your left elbow toward your right knee while extending your left leg.
  6. Continue alternating sides in a smooth and controlled pedaling motion.

Sets, reps and load

Start with 3 sets of 10 to 15 repetitions per side. Rest for 30 to 45 seconds between sets to maintain quality movement.

Since this is a bodyweight exercise, you make it harder by slowing down the tempo or extending your straight leg closer to the floor.

Common mistakes

  • Pulling on the neck. Rest your fingertips lightly behind your ears and let your core do the lifting. Do not interlock your fingers behind your head.
  • Moving too fast. Slow down the tempo to ensure your muscles are doing the work instead of momentum.
  • Arching the lower back. Tuck your pelvis slightly and press your lower back into the mat before you start moving.
  • Closing the elbows. Keep your elbows pointed wide to the sides so your torso has to rotate fully to complete the repetition.

Make it easier or harder

Easier

  • Keep your feet flat on the floor and march one knee up at a time as you twist.
  • Perform standard crunches without the rotational element to build basic core strength.

Harder

  • Add a two-second pause at the end of each rotation to increase time under tension.
  • Wear light ankle weights to increase the demand on your hip flexors and core.

Before you load it up

  • Twisting under load is something people with osteoporosis or a recent back injury are often advised to limit.

Swaps and related core exercises

Same muscle group with different equipment:

More bodyweight options:

Browse all bodyweight exercises or every core exercise.

When to see a doctor or physio

  • Sharp pain in your lower back during the rotation or leg extension.
  • A pinching sensation in the front of your hips that does not improve with a modified range of motion.
  • Neck pain or stiffness that persists after you finish the exercise.

This page is general training information, not medical advice. If you are new to strength training, managing a health condition, pregnant or coming back from an injury, check with a doctor or physio first.

How this page was made. Exercise data (equipment, muscles, mechanics, level) compiled by the Unite Journal Crew as a general anatomy guide, cross-checked against the public-domain free-exercise-db list. Text drafted with AI assistance and edited by the crew; see our house rules. Last checked October 2026.