Legs · Quads · Machine
Leg Extension
The leg extension is a seated machine exercise that straightens the knees against a pad on the shins. It is the only common exercise that isolates the quads, including the rectus femoris that squats train less, so it pairs well with squats and presses.
How to
Machine- 1 Sit with the pad on the lower shins.
- 2 Extend the legs to straight, pause.
- 3 Lower slowly to the start.
Tips
- Line up the knee with the machine's pivot.
- Hold the handles and keep the hips on the seat.
- Pause for a second with the legs straight.
Common mistakes
- Kicking the weight up with momentum.
- Letting the stack crash down.
- Lifting the hips off the seat.
Muscles worked
Main
- Quads
Breathing and bracing
Breathe out as you extend, breathe in as you lower.
Sets and reps
- Muscle size
- 3–4 sets of 10–15 reps, 1–1.5 min rest
- Where it fits
- After squats or leg presses, or as a warm-up before them
Setup
- 1 Set the back pad so the knees line up with the machine's pivot.
- 2 Set the shin pad just above the ankles.
- 3 Sit back and hold the handles.
- 4 Start with the knees bent to about 90° or a little more.
Technique in detail
- Straighten the legs until the knees are fully extended.
- Squeeze the quads for a second at the top.
- Lower slowly over two to three seconds.
- Keep the hips on the seat and the back against the pad.
In these plans
- PPL · 6 DAY · Legs B
- UPPER / LOWER · 4 DAY · Lower B
Variations and alternatives
Questions
Is the leg extension bad for the knees?
Not for healthy knees at a controlled tempo. If the knees hurt, shorten the range or lower the weight.
Toes pointed in or out?
Straight ahead is fine. Turning the toes barely changes which part of the quads works.
Should I pause at the top?
Yes. A one-second squeeze makes light weights count.
Log it in Volu(me)
Add Leg Extension to any workout. Next time the app fills in the weight and reps from your last session and marks a new best set the moment you tick it.