Strength Training · Bodybuilding
Leg Extension
The leg extension is a seated machine exercise that trains the front of your thighs by straightening your knees against resistance.
- Beginner
- Isolation
- Low injury risk
- Rest 1 min
How to do it
- Adjust the seat so your knees line up with the machine’s pivot when your back rests against the back pad.
- Position the roller across your lower shins, just above your ankles.
- Set the starting position with your knees comfortably bent.
- Grip the handles beside the seat.
- Straighten both knees to lift the roller.
- Bend your knees to return to the starting position.
Form cues
- Keep your hips planted.
- Move both legs evenly.
- Exhale as you lift.
Common mistakes
- Kicking the weight upUse a weight you can lift smoothly without swinging your torso.
- Dropping the weightTake about two seconds to lower the roller without letting the stack slam.
- Stopping every rep halfwayUse your full comfortable range rather than shortening the movement to lift more weight.
Safety
Excessive resistance or an unsuitable machine setup can aggravate your knees. Snapping into the top position can also stress the joint, especially as you tire.
- Check that all adjustment pins are fully engaged before starting.
- Try a light warm-up set to check the machine fit.
- Finish each extension without forcefully snapping your knees straight.
- Stop the set if you feel sharp or increasing knee pain.
If you have an ongoing knee problem or recent knee surgery, ask a physiotherapist or doctor about an appropriate load and movement range first.
Muscles worked
Primary muscles
Equipment
- Leg Extension Machine
Sets and reps
- Sets
- 2–3
- Target
- 10–15 reps
- Rest
- 1 min
Finish each set feeling you could complete about two more controlled reps.