Bent Knee Lying Twist — how to, muscles worked, alternatives

How to do the Bent Knee Lying Twist

Lie on your back, knees bent, arms out to the sides.
Lower both knees together to one side, shoulders on the floor.
Bring your knees back to the center.
Lower them to the other side and keep alternating.

Full technique — 7 steps

Lie on your back with your arms out to the sides, palms down on the floor.
Bend your knees and keep them together, feet flat on the floor side by side.
Press your shoulders and arms into the floor for the whole set.
Lower both knees together to one side, letting your hips roll with them.
Lower until your knees reach or nearly reach the floor, keeping both shoulders down.
Bring your knees back to the center using your obliques, then lower them to the other side.
Continue alternating sides at a slow, even pace.

Common mistakes

Swinging knees for momentum
Lifting a shoulder off the floor
Letting the knees drift apart
Lower back arching off floor

Form cues

Arms press into floor
Keep knees together
Shoulders stay down
Move slowly side to side

Substitutes by equipment

Same muscles, same movement — pick the version you have the gear for.

Where to start and where to go next

Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.

This exercise Bent Knee Lying Twist 10% of bodyweight
Harder Hyperextension Bench Oblique Crunch 40% of bodyweight
Harder Hanging Oblique Knee Raise 60% of bodyweight

Quick answers

What muscles does the Bent Knee Lying Twist work?

Primary: Obliques 8/10. Also works: Abs 5/10, Lower back 3/10.

When should I do the Bent Knee Lying Twist in a workout?

Warm-up. Done at the start to get the body ready. ≈ 4 min with rest.

How many sets and reps of the Bent Knee Lying Twist?

Strength: 2–3 sets of 8–12 reps, rest 1 min, 3 reps in reserve. Muscle growth: 3–4 sets of 10–16 reps, rest 1 min, 3 reps in reserve. Endurance: 2–3 sets of 16–24 reps, rest 45 s, 4 reps in reserve.

What can I do instead of the Bent Knee Lying Twist?

Cable machine: Cable Mid-to-Low Woodchop, Cable Horizontal Woodchop. Dumbbells: Dumbbell Russian Twist, Dumbbell Straight Leg Russian Twist. Barbell: Landmine Russian Twist, Seated Barbell Twist. Resistance bands: Resistance Band Bicycle Crunch.