Bicycle Crunch: How to Do It Correctly

Step-by-step form

1. Setting up

   Lie on your back, lightly press the lower back toward the floor, and bring the knees to a 90-degree tabletop position. Hands rest lightly beside the ears; fingers should not pull on the neck. Tuck the chin slightly and bring the rib cage toward the pelvis to prepare the abdominals.

2. The movement

   Bring the right elbow toward the left knee while extending the right leg under control. Switch sides smoothly without collapsing to the center: left elbow approaches right knee as the left leg extends. The movement should come from trunk rotation and controlled leg extension, not from forcing elbow-knee contact. Both sides together may count as one full repetition.

3. What stays in line

   The lower back should not lift from the floor; the lower the extended leg travels, the greater the lumbar demand. Do not close the elbows around the face; the rib cage should rotate, not just the arm. Keep the neck neutral and avoid jamming the chin to the chest. The pelvis should remain steady without rocking side to side.

4. Breathing

   Exhale briefly and controlled on each cross-body crunch; inhale through the nose during the side switch. At slower tempo, match the right+left cycle to a 2-3 second breathing rhythm. Avoid breath-holding so the neck does not tense.

Common mistakes

1) Pulling the neck: if the chin jams to the chest or the back of the neck hurts, the hands are pulling too hard. 2) Lowering the legs too far: if the lower back lifts, the leg angle is too low. 3) Pedaling too fast: if rotation disappears and only the hip flexors work, the tempo is too fast.

Recommended sets and reps

Recommended sets and reps

Beginner: 2 sets x 8-10 reps/side. Intermediate: 3 sets x 12-20 reps/side. Advanced: slow tempo or isometric squeeze 4 sets x 20-30 reps/side.

Tempo

Beginner: 2-0-2-0 (2 s right, no pause, 2 s left). Intermediate: 1-1-1-0 (1 s close, 1 s squeeze, 1 s switch). Advanced: 3-1-3-0 (3 s rotation, 1 s isometric squeeze, 3 s to the other side).

How often

Appropriate 2-4 days per week as core work; leave 48 hours between sessions if lower-back or neck sensitivity exists. Low-volume technique sets can be repeated after 24 hours. Avoid stacking high volume with heavy hip-flexor work or intense plank days.

What it trains

Trains rectus abdominis and obliques together, improving rotational core strength. Cross-body arm-leg coordination improves trunk control and rhythmic movement skill. Slow tempo targets lumbar-pelvic control, while faster tempo emphasizes core endurance.

If something hurts

Knee

Knee pain usually comes from aggressive knee lockout or tension through the hamstring/hip flexor line while extending the leg. Keep a slight bend in the knee and extend the leg higher above the floor. If pain is sharp or felt inside the joint, stop and consult a healthcare professional.

Lower back

Lower-back pain occurs when the extended leg drops too low and the pelvis tips anteriorly. Immediate modification: keep the leg 45-60 degrees higher, regain lower-back contact, and slow the tempo. If pain does not resolve within 1-2 reps or radiates into the leg, stop and consult a healthcare professional.

Shoulder

Shoulder pain usually comes from tensing the neck/shoulder muscles while forcing elbows toward the knees. Move the hands away from the head and cross them on the chest, rotating from the rib cage. If pain is sharp or radiates down the arm, stop and consult a healthcare professional.

When to skip it

Avoid with acute lumbar disc/sciatic flare, neck pain or cervical disc issues, uncontrolled diastasis recti, hip-flexor tendinopathy, or early recovery after abdominal surgery. For neck-sensitive users, dead bug is a safer starting option.

Where to go next

Moves that train the same thing — and, where this one sits on a ladder, the rungs either side of it.

• Decline Push-up→
• Diamond Push-up→
• Donkey Kick→
• Leg Raise→
• Seated Knee Tuck→
• Step-up→