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Gym Equipment Explained: Leg Extension Machine

I'm sure you've seen the Leg Extension Machine at the gym but what does it do, and how do you even begin to use it? Here's the rundown on the Leg Extension Machine.

What: The Leg Extension Machine is an exercise machine that you can use to build muscle in your legs and stronger knee joints.
Area of body it works: Quads, primarily.
Why: The leg extension machine has gotten a bad rep in recent years as being dangerous for the knee, but if done properly, it can be a very effective way of strengthening the quads.
How: To see how to use the machine, just


  • When seated, adjust the footpad so it rests on the lowest part of the shins (or higher up the leg to reduce stress on knees). Adjust the back of the pad so that your back is flat against it. Keep your abdominal muscles tight, knees bent and chest up. Select a weight that suits you.
  • Hold on to the handles on the sides of the machine and start the upward motion by extending your legs until your knees are straight, but not locked.
  • Then slowly lower the weight back to the starting position to complete one.
  • Do three sets of 10.


Join The Conversation
ilovecandyfloss ilovecandyfloss 9 years
I'm a gym instructor, and I always tell my clients NOT to fully extend their legs, as it puts too much strain on the knees! Its important not to lock your joints out, so remember to just take it to 90% straight!
1stharbinger 1stharbinger 9 years
I love this machine. I dance so while you may not use this motion regularly in nature, we do a lot of leg extensions in dance. But I hadn't heard it can hurt your knees. What can we do to avoid that?
quinnunc quinnunc 9 years
I've heard from several sources over the years that the leg extension machine has been contraindicated. As I understand, it forces your quads to contract while they are in an unnatural position to contract (as in, where in nature will we ever need to make a motion like this?). Also something about the muscle contracting with the possibility of being a split-second off-timed, and causing great damage in the knees. Or something. I used to love it, but I haven't touched it in a few years because of this.
Renees3 Renees3 9 years
i like this machine, I love the burn. Except it's kind of silly looking
gumdrops334 gumdrops334 9 years
I used this machine yesterday
aimeeb aimeeb 9 years
I love it too!
VicVicVictooriaa VicVicVictooriaa 9 years
I love this really aids in my running
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