# Leg Extension

A machine isolation exercise targeting the quadriceps. Useful for adding direct knee-extension volume without loading the hips or spine heavily.

- Beginner · Isolation
- Equipment: Leg extension machine
- HD video: https://media.seto.fit/exercises/lever-leg-extension/video/male.mp4
- HTML: https://seto.fit/exercises/leg-extension/

## Muscles worked

- Quads: 10/10

## How to do the Leg Extension

1. Sit on the machine and adjust the seat so your knees align with the pivot point.
2. Place your shins behind the lower roller and grip the handles securely.
3. Extend your knees until they are nearly straight, feeling the muscles in front of your thighs.
4. Slowly lower the weight back to the starting position.

### Full technique — 6 steps

1. Adjust the seat so your knees line up with the machine's pivot point.
2. Sit back against the pad and place your shins behind the lower roller.
3. Grip the handles and start with knees bent comfortably under the pad.
4. Extend your knees until your legs are nearly straight and quads fully shortened.
5. Squeeze the quadriceps briefly at the top without kicking or snapping the weight up.
6. Lower the pad back down until your knees are bent and the weight stack stays under control.

## Common mistakes

- Knees set forward of pivot
- Kicking the weight upward
- Hips lifting off seat
- Stopping short of top range
- Slamming the weight stack down

## Form cues

- Align knees with pivot
- Keep back against seat
- Move only at knees
- Squeeze the top

## How much to do

- **Muscle growth** (best fit): 3–4 sets of 8–12 reps · rest 1 min 15 s · 2 reps in reserve · lower 2 s, pause 1 s, lift 2 s
- **Endurance** (good fit): 2–3 sets of 15–20 reps · rest 45 s · 3–4 reps in reserve · lower 2 s, lift 2 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.

- **No equipment**: [Bodyweight Single Leg Extension](https://seto.fit/exercises/bodyweight-single-leg-extension/)

## 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: Leg Extension — Beginner**
- Harder: [Standing Cable Leg Extension](https://seto.fit/exercises/standing-cable-leg-extension/) — Intermediate

## Quick answers

### What muscles does the Leg Extension work?

Primary: Quads 10/10.

### When should I do the Leg Extension in a workout?

Finisher. Goes last, once the heavy work is done. ≈ 6 min with rest.

### How many sets and reps of the Leg Extension?

Muscle growth: 3–4 sets of 8–12 reps, rest 1 min 15 s, 2 reps in reserve. Endurance: 2–3 sets of 15–20 reps, rest 45 s, 3–4 reps in reserve.

### What can I do instead of the Leg Extension?

No equipment: Bodyweight Single Leg Extension.

### What is a harder version of the Leg Extension?

Standing Cable Leg Extension (Intermediate).

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

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