Lying Bicycle Crunch

How to do the Lying Bicycle Crunch

1. 1Lie flat on your back on a mat with your knees bent and feet lifted so your shins are parallel to the floor.
2. 2Place your fingertips lightly at the sides of your head, elbows pointed out, without interlacing your fingers behind your neck.
3. 3Brace your core and press your lower back gently into the mat before moving.
4. 4Curl your shoulder blades off the mat and rotate your right elbow toward your left knee while simultaneously extending your right leg out straight at roughly 45 degrees.
5. 5Pause briefly at the point of peak rotation, feeling your abs fully contract.
6. 6Reverse the motion smoothly, rotating your left elbow toward your right knee while extending your left leg, as if pedaling a bicycle.
7. 7Continue alternating sides in a controlled rhythm, keeping both shoulder blades off the mat throughout.
8. 8Complete the target number of reps per side, then lower your feet and head back to the mat.

Form tips

• Lead the rotation from your shoulder blade, not your elbow — think about bringing your chest across toward the opposite knee rather than pulling your head with your hand.
• Keep the extended leg low to the floor (around 45 degrees) to increase rectus abdominis engagement; the lower the leg, the harder the abs work.
• Move at a deliberate, even tempo rather than rushing — rapid swinging reduces muscle tension and turns the movement into momentum.
• Exhale as you rotate toward the knee and inhale as you return to center to maintain intra-abdominal pressure throughout.
• Keep your lower back pressed into the mat at all times; if it lifts, raise your legs slightly higher until you rebuild the strength to lower them.

Common mistakes

• Pulling on the back of the head or neck to initiate rotation, which strains the cervical spine and shifts effort away from the abs.
• Allowing the shoulder blades to drop back to the mat between reps, which releases core tension and turns the exercise into two separate crunches instead of a continuous contraction.
• Pedaling too fast and using momentum, which reduces time under tension for the rectus abdominis and iliopsoas and diminishes the training effect.
• Letting the lower back arch off the mat, especially as the legs extend, which removes core bracing and places excessive stress on the lumbar spine.
• Bringing elbows to knees rather than rotating the torso — true rotation comes from the trunk, not from hunching the shoulder forward.

Frequently asked questions