Legs · Machine
Leg Extension
How to do the leg extension, the muscles it works, and the mistakes to avoid. Pulled straight from the Kovo app's exercise library.

- Equipment
- Machine
- Difficulty
- Beginner
- Logged as
- Weighted reps
- Movement
- Extension
- Mechanic
- Isolation
See it in motion

How to do it
Sit on a leg extension machine with your back against the backrest and the front of your ankles against the padded roller. Grasp the handles on the sides for stability. Extend your legs to lift the weight until your legs are almost straight, then slowly lower the weight back to the starting position.
- 1Sit back in the leg extension machine and extend your knees to lift the pad; you should feel your quadriceps contracting strongly
- 2Pause at the top and squeeze, then lower slowly to feel a stretch
- 3Keep your back against the pad and toes relaxed
Common mistakes
- Don't lock your knees abruptly at the top, maintain control
- Avoid leaning back or arching your lower back
- Don't use momentum or swing the weight up, focus on the muscle contraction
Muscles worked
The leg extension mainly works the quads.
- QuadsPrimary
- GlutesMinor
- HamstringsMinor
- CalvesMinor
Kovo programs the leg extension for you and tracks it every session.
The AI builds your whole program, drops the right lifts into each workout, and adjusts your weights as you get stronger. Free on iOS and Android.
More quads exercises
- How to do the barbell squat
- How to do the split squat
- How to do the step-up
- How to do the lunge
- How to do the squat
- How to do the bulgarian split squat
Last reviewed April 2026.
