# Bench Knee Tuck

A seated core exercise on a flat bench, holding the bench beside your hips while you pull your knees toward your chest and extend your legs out again. Trains the abs, with the hip flexors helping.

- Beginner · Isolation
- Equipment: Flat bench
- HD video: https://media.seto.fit/exercises/bench-knee-tucks/video/male.mp4
- HTML: https://seto.fit/exercises/bench-knee-tuck/

## Muscles worked

- Abs: 9/10
- Obliques: 5/10
- Lower back: 3/10

## How to do the Bench Knee Tuck

1. Sit on the bench edge, hands holding the bench beside your hips.
2. Lean back slightly and lift your feet off the floor.
3. Pull your knees toward your chest, then extend your legs out.
4. Keep your feet off the floor between reps.

### Full technique — 6 steps

1. Sit on the edge of a flat bench and hold the sides of the bench beside your hips.
2. Lean your torso back slightly and lift both feet off the floor.
3. Tighten your stomach and keep your ribs pulled down.
4. Exhale and bend your knees and hips to draw your knees toward your chest.
5. Extend your legs straight forward and slightly down, keeping your feet off the floor.
6. Begin the next rep from the extended position without resting your feet on the floor.

## Common mistakes

- Letting the lower back arch
- Dropping heels between reps
- Swinging legs with momentum
- Bending knees to shorten range
- Leaning too far back on the bench

## Form cues

- Keep ribs down
- Exhale pulling in
- Reach legs long
- Keep feet off floor

## How much to do

- **Strength**: 3 sets of 8–12 reps · rest 1 min · 2 reps in reserve · lower 2 s, lift 1 s, pause 1 s
- **Muscle growth** (good fit): 3–4 sets of 12–20 reps · rest 1 min · 2–3 reps in reserve · lower 2 s, lift 1 s, pause 1 s
- **Endurance** (best fit): 2–3 sets of 20–25 reps · rest 45 s · 3–4 reps in reserve · lower 1 s, lift 1 s

Reps in reserve: how many more you could still do when you end the set.

## Substitutes by equipment

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

- **Barbell**: [Barbell Overhead Sit-Up](https://seto.fit/exercises/barbell-overhead-sit-up/)
- **Resistance bands**: [Resistance Band Dead Bug](https://seto.fit/exercises/resistance-band-dead-bug/), [Lying Resistance Band Crunch](https://seto.fit/exercises/lying-resistance-band-crunch/)
- **Weight plates**: [Plate Overhead Sit-Up](https://seto.fit/exercises/plate-overhead-sit-up/)
- **Suspension trainer**: [Suspension Trainer Mountain Climbers](https://seto.fit/exercises/suspension-trainer-mountain-climbers/), [Supine Suspension Trainer Knee Tuck](https://seto.fit/exercises/supine-suspension-trainer-knee-tuck/)

## Where to start and where to go next

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

- Easier: [Ab Wheel Straight Arm Crunch](https://seto.fit/exercises/ab-wheel-straight-arm-crunch/) — 15% of bodyweight
- **This exercise: Bench Knee Tuck — 20% of bodyweight**
- Harder: [Reverse Crunch](https://seto.fit/exercises/reverse-crunch/) — 25% of bodyweight
- Harder: [Ab Wheel Pass Crunch](https://seto.fit/exercises/ab-wheel-crunch/) — 30% of bodyweight

## Quick answers

### What muscles does the Bench Knee Tuck work?

Primary: Abs 9/10. Also works: Obliques 5/10, Lower back 3/10.

### When should I do the Bench Knee Tuck in a workout?

Finisher. Goes last, once the heavy work is done. ≈ 5 min with rest.

### How many sets and reps of the Bench Knee Tuck?

Strength: 3 sets of 8–12 reps, rest 1 min, 2 reps in reserve. Muscle growth: 3–4 sets of 12–20 reps, rest 1 min, 2–3 reps in reserve. Endurance: 2–3 sets of 20–25 reps, rest 45 s, 3–4 reps in reserve.

### What can I do instead of the Bench Knee Tuck?

Barbell: Barbell Overhead Sit-Up. Resistance bands: Resistance Band Dead Bug, Lying Resistance Band Crunch. Weight plates: Plate Overhead Sit-Up. Suspension trainer: Suspension Trainer Mountain Climbers, Supine Suspension Trainer Knee Tuck.

### What is an easier version of the Bench Knee Tuck?

Ab Wheel Straight Arm Crunch (15% of bodyweight).

### What is a harder version of the Bench Knee Tuck?

Reverse Crunch (25% of bodyweight), Ab Wheel Pass Crunch (30% of bodyweight).

How we rate exercises: https://seto.fit/guides/methodology/

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