Lying Knee Tuck

Muscles worked

Setup

1. Lie flat on your back on a mat with your legs fully extended.
2. Place your hands flat on the floor by your sides or slightly under your glutes for additional lower back support.
3. Engage your core by pressing your lower back firmly into the floor to eliminate any arch.

How to do it

1. Exhale and pull your knees toward your chest by flexing at the hips and knees simultaneously.
2. Squeeze your abdominals at the top of the movement, bringing your knees as close to your torso as possible without lifting your mid-back.
3. Inhale and slowly extend your legs back to the starting position using a controlled 2-second tempo.
4. Stop just before your heels touch the ground to maintain constant tension on the abs.

Form checklist

• Keep your lower back glued to the floor at all times.
• Avoid using momentum or swinging your legs.
• Keep your neck neutral and shoulders relaxed to avoid strain.
• Ensure your feet do not touch the floor between repetitions.

Pro tips

• Focus on 'curling' your pelvis toward your belly button at the peak of the movement to maximize lower abdominal recruitment.
• Slow down the eccentric (lowering) phase to increase time under tension and improve core control.

Make it harder

• Perform the movement with straight legs (Leg Raises) to increase the lever length and resistance.
• Add a 'hip lift' or reverse crunch at the top of the tuck, driving your feet toward the ceiling.

Frequently asked

What muscles does the lying knee tuck work?

The lying knee tuck primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.

What equipment do you need for the lying knee tuck?

The lying knee tuck requires no equipment — just your body weight.

Is the lying knee tuck good for beginners?

Yes. The lying knee tuck is a beginner-friendly movement and a strong foundation to build on.

Related exercises

• 3/4 Sit-UpBeginner · abs and obliques
• 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
• 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
• 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals