For gyms
Reverfit for gymsReverfit for boxesPricingFree
Leg extension
The machine that isolates the quads like no other. It has a bad reputation when it comes to knees, and most of that reputation comes from using it with too much weight and jerky reps.
What it works
- Quads, the four muscles on the front of your thigh, with no help from anything else
- Especially the rectus femoris, which gets little work in the squat
How to do it
- 1Adjust the backrest
Sit with your back supported and your knee right at the machine's pivot point. If your knee is in front of or behind the pivot, the joint works at an angle.
- 2Position the roller pad
On your ankle, not on the top of your foot or mid-calf. If it presses on the bone, move it up a finger's width.
- 3Straighten your knee to lift
No jerking. All the way to the top and hold for a second, squeezing your thigh: that moment at the top is what pays off most in this exercise.
- 4Lower under control
For a count of two, without letting the weight drop and slam the stack. Go as low as the machine lets you, without stopping halfway.
The mistakes you see most
- Using your hips for momentum. Lifting your butt off the seat to get the weight moving. Hold the handles and stay against the backrest.
- Dropping the weight. Letting it fall cuts out half the exercise and makes needless noise. The lowering is as much a part of the exercise as the lifting.
- Knee out of line with the pivot. The most common setup mistake. Two seconds adjusting the backrest completely changes how the set feels.
- Too much weight. The lever here is very long. If you have to swing to move the weight, there's too much of it.
Variations
- Single-leg. Evens out the weaker side and stops the stronger one from covering for it. Very useful after an injury, if your physical therapist says so.
- With a pause at the top. Two or three seconds holding at the top on every rep. Tough and very effective with little weight.
- With the backrest reclined further. Leaning the backrest back stretches the rectus femoris more and the exercise becomes more demanding.
- Partial reps at the end. When you can't get full reps anymore, finish with short reps at the top. A cheap way to push the set further.
Frequently asked questions
Is it bad for your knees?
Done with a reasonable load, a controlled range and your knee lined up with the machine's pivot, it's an exercise commonly used to strengthen the quads. What does cause trouble is excessive weight with jerky reps. If you have a knee injury, the person who decides what to do is your physical therapist or your doctor.
Does it replace the squat?
No. The squat moves your whole leg and your hips at once; the extension works only the quads. They complement each other: the machine reaches a part of the quads the squat barely touches.
Do I need to straighten all the way at the top?
Yes, reaching the top is what this exercise gives you most. Snapping into lockout with heavy weight is another matter, and that's what you want to avoid.
How many reps?
Ten to twenty. It's a machine where long sets feel good and let you push hard without needing heavy loads.
And to keep track of what you lift
In the Reverfit Workout app every exercise comes with its animation, and you log the weight and reps set by set, with what you did last time right in front of you. Free and with no ads.
Workout
