Form cues
- Keep core tight
- Don't arch lower back
- Lead with chest
- Controlled split
Exercise
Jackknife Split Crunch
Waist, body weight
A crunch variation combining a V-up with a leg split to target the abs and hip flexors.
Target: rectus abdominis. Also works: hip flexors, obliques, adductors.
Steps
- Lie on your back with arms extended overhead and legs straight.
- Engage your core and simultaneously lift your torso and legs off the ground.
- As you rise, spread your legs into a split while reaching your hands toward your feet.
- Pause at the top, squeezing your abs.
- Lower your legs and torso back to the ground with control, bringing feet together.
Common mistakes
- Swinging the legs
- Using momentum
- Arching the lower back
Breathing
Exhale when crunching up, inhale when lowering down.
In the app, search for Jackknife Split Crunch and add it to a workout.