Exercise · Legs and glutes
Leg extension machine
The leg extension is a machine exercise that isolates your quadriceps. You sit, then straighten and bend your legs against a weight. It’s a solid way to focus on your thighs when your gym has the machine, which is the case in almost all gyms tracked by GoSet in Quebec.
Doable at all 76 gyms GoSet follows
The essentials
- Line your knees up with the pivot.
- Straighten your legs, pause, then lower slowly.
Muscles worked
- Primary
- Quadriceps
How to do it
- Sit on the machine and adjust the backrest so the back of your knee sits right at the edge of the seat.
- Set the machine so your knees line up with the pivot, then place the pad just above your ankles.
- Keep your back against the pad, grab the handles, feet about hip-width apart, and start with your knees bent around 90 degrees or a bit more.
- Take a breath in, squeeze your thighs and straighten your legs over about 1–2 seconds until they’re almost fully straight, without snapping your knees.
- Pause briefly at the top, keep the tension in your quads, and breathe out.
- Lower the weight slowly over 2–3 seconds back to the starting position under control, then repeat.
Common mistakes
Knees not lined up with the pivot
Instead : Move the seat forward or back and adjust the pivot so your knees line up with the machine’s axis before adding more weight.
Snapping the knees at the top
Instead : Stop just shy of fully locking out your knees, keep a slight bend, and control the lift over 1–2 seconds with a short pause at the top.
Hips shifting or back lifting off
Instead : Keep your hips and lower back pressed into the backrest, hold the handles firmly, and use a weight that lets you stay stable through the full movement.
Dropping the weight too fast
Instead : Think about “braking” the weight on the way down. Use 2–3 seconds on the lowering phase to stay in control and feel your quadriceps more.
Coach tips
- Start with a lighter weight to test the setup: if your knee feels off, stop and adjust the seat or pad before you go heavier.
- Keep a steady breathing rhythm: inhale at the bottom before you push, exhale as you straighten your legs.
- If you want more control, hold for about one second at the top, squeezing your quads hard before lowering slowly.
- To progress, build up your reps with solid form first, then increase the weight gradually over the weeks.
Variations
- You can use lighter weight sets at the end of your workout, with a controlled tempo, to focus on feeling your quadriceps.
- You can do single-leg sets if the machine allows it, to focus on each side separately.
Sets and reps
In strength training, leg extensions are often done for 3–4 sets of 8–15 reps, depending on the load and your level. Many people use them near the end of a session to train the quadriceps with more control.
Equipment
Alternatives for the same muscles
Log your Leg extension sets with GoSet
GoSet remembers your last time, starts your rest on its own and notes your records. Even with no signal in the basement. Coming soon to iPhone and Android.
Common questions
Where should I feel leg extensions?
You should mainly feel them in the front of your thigh, in the quadriceps. If you feel pain in your knee or somewhere else, stop the exercise and talk to a professional.
Should I fully lock out my knees?
You can straighten your legs almost all the way, but keep a tiny bend so you’re not snapping the knees. Focus on squeezing your quadriceps, not on locking out hard.
What if my knees feel uncomfortable on the machine?
First, lower the weight and make sure your knees line up with the pivot. You can also shorten the range of motion a bit. If the pain stays, stop and talk to a professional.
Where should the pad sit on my legs?
The pad should rest just above your ankles, not on your toes and not too high on your shin. That way the movement feels more comfortable and easier to control.