Exercise guide
Lying Bent Legs Raise
- Beginner
- Isolation
- Rep-based
- Waist
The Lying Bent Legs Raise is a foundational core exercise that isolates the lower abdominals while minimizing strain on the lower back by shortening the lever arm of the legs.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back on a mat with your arms at your sides or hands tucked slightly under your glutes for lumbar support.
- Bend your knees to a 90-degree angle and lift your feet so your shins are parallel to the floor.
- Press your lower back firmly into the mat, eliminating any gap between your spine and the floor.
How to do it
- Inhale and slowly lower your bent legs toward the floor, keeping the 90-degree angle at the knees constant.
- Lower your feet until they are just an inch above the ground, or as far as you can go without your lower back arching.
- Exhale and use your lower abdominals to pull your knees back up to the starting position over your hips.
- Maintain a controlled tempo: 2 seconds down, 1 second pause at the bottom, and 1 second up.
Form checklist
- Keep your lower back glued to the floor throughout the entire range of motion.
- Maintain a consistent 90-degree bend in the knees; do not let your feet kick out or tuck in.
- Keep your head and shoulders relaxed on the mat to avoid unnecessary neck strain.
- Move slowly and avoid using momentum to swing the legs back up.
Pro tips
- Focus on a posterior pelvic tilt—tucking your tailbone toward your belly button—to maximize recruitment of the lower rectus abdominis.
- Pause for a split second at the bottom of the movement to eliminate elastic energy and force the core to initiate the lift.
Make it harder
- Slow down the eccentric (lowering) phase to 4-5 seconds to increase time under tension.
- Perform a small hip lift (reverse crunch) at the top of the movement to further engage the deep core muscles.
Frequently asked
- What muscles does the lying bent legs raise work?
- The lying bent legs raise primarily targets the abs, and also works the obliques as secondary muscles.
- What equipment do you need for the lying bent legs raise?
- The lying bent legs raise requires no equipment — just your body weight.
- Is the lying bent legs raise good for beginners?
- Yes. The lying bent legs raise is a beginner-friendly movement and a strong foundation to build on.