Also known as: knee raises, knee tucks, supine knee raises, lying knee tucks, supine knee tucks

What is Lying knee raises?

Lying knee raises are a simple bodyweight core exercise performed on your back, lifting the knees toward the chest to target the lower abs and hip flexors. They are rated easy for beginners and emphasize controlled movement and lower-back stability.

How to Do Lying knee raises

  1. Set up: Lie flat with legs extended and hands by your sides or under hips. Press your lower back into the mat and breathe evenly to prepare.
  2. Engage core: Exhale and draw your belly button toward your spine, bracing the core to keep the lower back in contact with the floor throughout the movement.
  3. Lift knees: Slowly bend and lift your knees toward your chest until thighs approach a 90-degree angle, using control rather than momentum to move.
  4. Lower slowly: Lower your legs with control until just above the floor without letting feet touch; maintain the lower-back connection and steady breathing.
  5. Repeat safely: Perform recommended reps with steady tempo, rest between sets, and stop if you experience sharp lower-back pain or undue strain.

Muscle Groups

Core

Description

Lie flat on your back with legs extended. Place your hands by your sides or under your hips for support. Keep your lower back pressed into the ground as you lift your knees toward your chest. Lower slowly without letting your feet touch the floor. Control the movement to fully engage your core.
Movement Group: Core
Equipment: None (bodyweight only)

Progressions and Regressions

Frequently Asked Questions

What are the benefits of lying knee raises?

Lying knee raises strengthen the lower abs and hip flexors, improve core endurance and pelvic stability, and require no equipment. They help beginners build foundational core control and can reduce lower-back strain when done with proper form.

What common mistakes should I avoid when doing lying knee raises?

Avoid arching the lower back, using momentum to swing the legs, and letting feet hit the floor between reps. Don’t hold your breath; keep hands placed for support and focus on controlled range of motion.

How can I progress or regress lying knee raises?

Regress with bent-knee marches, supported knee tucks, or shorter ranges of motion. Progress by performing straight-leg raises, hanging knee raises, adding slow negatives, or light ankle resistance once form and core control are solid.