Bicycle Crunch
The bicycle crunch is a floor abdominal exercise that combines a crunch with a twist, bringing each shoulder towards the opposite knee while the legs pedal. It works the rectus abdominis and the obliques together, with the hip flexors driving the legs.
Also called: Bicycle Sit-Up, Cross-Body Crunch, Bicycle Manoeuvre, Bicycle Maneuver · Equipment: bodyweight · Pattern: isolation
Step by step
- Lie on your back with your knees bent and feet flat. Rest your fingertips lightly behind your ears with your elbows wide.
- Press your low back gently into the floor. Curl your shoulder blades off the floor and lift your feet so your knees are over your hips and your shins are level with the floor.
- Rotate your trunk to bring your right shoulder towards your left knee as you draw that knee in and straighten your right leg out, about 45° from the floor.
- Switch sides: rotate your left shoulder towards your right knee as your left leg straightens. Turn through your ribcage and keep your elbows wide.
- Keep a slow, steady rhythm, with your shoulder blades off the floor and your low back in contact with it for the whole set. If your back starts to arch, raise the straight leg higher.
- Breathe out as you rotate and in as you switch sides.
- After the last rep, bring both feet to the floor and rest your head and shoulders back down.
- Shoulder to knee, not elbow to knee
- Low back pressed into the floor
- Slow legs, full rotation
- Elbows wide, hands light behind your head
- Straight leg long and off the floor
In VALDA, these cues are one tap away on the exercise while you train.
What it trains
| Muscle | Role | Evidence |
|---|---|---|
| Rectus abdominis: upper | Prime mover | C |
| Obliques (internal/external) | Prime mover | C |
| Rectus abdominis: lower | Secondary | C |
| Hip flexors | Secondary | C |
| Transverse abdominis | Stabiliser | C |
Evidence grades: A = strong research base · B = good · C = limited · D = coaching consensus.
What goes wrong, and the fix
Pulling on the head
Fix: Keep your fingertips light behind your ears and rotate from your ribcage.
Elbow chasing the knee
Fix: Aim your shoulder, not your elbow, at the opposite knee.
Low back arching off the floor
Fix: Raise the straight leg higher until your low back stays on the floor.
Pedalling too fast
Fix: Slow the tempo so each side gets a full, controlled rotation.
Shoulders resting on the floor between reps
Fix: Keep your shoulder blades off the floor for the whole set.
What the research says
Endurance · first choiceMuscle growthGeneral fitnessFat loss & conditioning
- Muscle activity — In an EMG comparison of 13 common abdominal exercises, the bicycle crunch recorded the highest rectus abdominis activity and ranked among the highest for the obliques. EMG measures muscle activity, not growth.
- Rep ranges — Research finds lighter, higher-rep work favours local muscular endurance. The bicycle crunch is usually trained for reps or time, often in circuits.
- Effort — Studies show growth rises as sets get closer to failure, with a flattening curve, so finishing a rep or two short captures most of the benefit.
- Progression — A common approach is to slow the tempo, add a pause at each rotation or add reps. There is no direct research comparing these options.
Swap it mid-workout
With VALDA Pro, FLEX offers alternatives like these when you swap an exercise mid-workout.
Log the bicycle crunch in VALDA, with these cues one tap away while you train and your history for it in one place.
General information about exercise technique, not medical advice. If you have an injury or a health condition, your healthcare provider is the right person to ask.