# Bicycle Crunch: how to do it

- Main muscles: abs, obliques
- Also works: hip flexors
- Equipment: bodyweight
- Level: beginner
- 3D demo (side view): https://media.trainaq.com/exercises/bicycle_crunch/a62f3d1a06/side-m-720.mp4

## Steps

1. Lie on your back with fingertips behind your head and knees bent over your hips.
2. Lift your head and shoulders slightly off the floor.
3. Bring one knee in as you straighten the other leg and turn your opposite shoulder towards that knee.
4. Pause briefly, then switch sides in a smooth, steady rhythm.

## Cues

- Turn your ribs, not your elbow.
- Lower back stays on the floor.
- Slow and controlled beats fast.

## Common mistakes

- Pulling on your neck: keep your elbows wide and hands light.
- Going too fast: pause for a second on each side.
- Back arching: keep the straight leg higher off the floor.

## The version in our demo

Slow, controlled bicycle crunch with fingertips behind the head and a 1 s pause on each side, as ACE teaches it. The fast "pedalling" version is the same shape at a quicker tempo.

## Starting position

Lying on the back, fingertips lightly behind the head, elbows wide. Head, neck and shoulder blades lifted just off the mat and held there. Both legs raised with hips at 90° (thighs vertical) and knees at 90° (shins parallel to the floor), knees hip width apart, feet relaxed. Lower back on the mat.

## The movement

At the same time, draw the right knee in towards the chest while the left leg straightens out long, off the floor; curl and turn the trunk so the left elbow (really the left shoulder) moves towards the right knee. Pause briefly, then swap in one smooth movement: the left knee comes in, the right leg straightens, and the trunk turns so the right elbow moves towards the left knee. The rotation comes from the ribcage, not the hips; the pelvis and lower back stay flat on the mat.

## Breathing

Breathe out into each twist, in as you switch.

## Form in numbers

- Start: hip flexion 90°, knee flexion 90° (source); shoulder blades 3–5 cm off the mat.
- Elbow stops 5–15 cm from the knee; elbows stay wide, hands never pull the head.

## Sources

1. [ACE, "Supine Bicycle Crunches"](https://www.acefitness.org/resources/everyone/exercise-library/241/supine-bicycle-crunches/)
2. [StrengthLog, "How to Do Bicycle Crunch: Muscles Worked & Proper Form"](https://www.strengthlog.com/?p=31656)

Source: https://trainaq.com/exercises/bicycle-crunch