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LEG EXTENSIONS – Are they good or bad for you?

LEG EXTENSIONS – Are they good or bad for you?

There seems to still be out in debate on how greater benefit leg extension can be for training resistance it is better to be on the safe side don’t do too many at greater weights or do 100 reps try to do what you can in the minute then repeat. At Venus Fitness for Women we have adopted the old Contours way of training where you do one board then one resistance machine it helps by incorporating Cardio in Short burst that helps burn those extra kilojoules on every visit.

I found this interesting Article from

Leg extensions are exercises usually done with a lever machine in a gym. You sit on a padded seat and raise a padded bar with your lower legs. The exercise works mainly the quadriceps muscles of the front of the thigh—the rectus femoris and the vastus muscles.

Technically, this is an “open chain kinetic” exercise to distinguish it from “closed chain kinetic exercises” such as squats. The difference is that in the squat the body part being exercised is anchored (feet on the ground), while in the leg extension it is free to move with the leg extension (the padded bar moves), and thus the chain of movement is open in the leg extension.

The Leg Extension Benefits Debate

A relatively passionate debate has arisen in fitness circles with regard to the safety of leg extension exercises. Critics say that open chain exercises like the leg extension can damage the knees and that even full depth squatting is safer. Many trainers seem to have gone along with the loudest voices, avoiding leg extensions.

From reading quite a few opinions on this, including scientific and biomedical opinions, my position is somewhere in between. This is not sitting on the fence, however; this is a considered opinion that leg extensions can be used safely given a few precautions.

Doing Leg Extensions Safely

  • If you have a knee/thigh to be rehabilitated, seek guidance from a qualified physical therapist, or strength and conditioning coach who specializes in weight training rehabilitation. Don’t be surprised if they say to avoid the leg extension machine, though not all will.
  • Don’t lift heavy. This is not the machine to be trying out for a maximum lift (1RM), or even low-rep, high-load strength conditioning.
  • Don’t do more than around 3 sets of 8 to 12 reps at moderate load. You don’t need to do any so-called endurance sets with high repetitions on the leg extension machine.
  • Don’t use the leg extension exercise exclusively for quadriceps development. Feel free to include it in a program that also includes squats for lower body conditioning for variety if you wish.

If you follow this sensible approach, you don’t need to be afraid of practical use of a machine that may help in your training or rehabilitation.


Tagesson, S., Oberg, B., Good, L., and Kvist, J. (2007). A comprehensive rehabilitation program with quadriceps strengthening in closed versus open kinetic chain exercise in patients with anterior cruciate ligament deficiency: a randomized clinical trial evaluating dynamic tibial translation and muscle function. Am J Sp. Med. 36(2): 298–307.

Cohen, Z.A., Roglic, H., Grelsamer, R.P., Henry, J.H., Levine, W.N., Mow, V.C., and Ateshian, G.A. (2001). Patellofemoral stresses during open and closed kinetic chain exercises. Am. J. Sp. Med. 29(4): 480.

Fleming, B.C., Oksendahl, H., and Beynnon, B.D. (2005). Open-or closed-kinetic chain exercises after anterior cruciate ligament reconstruction? Exerc. Sport Sci. Rev. 33(3): 134–140.

Morrissey, M.C., Drechsler, W.I., Morrissey, D., Knight, P.R., Armstrong, P.W., and McAuliffe, T.B. (2002). Effects of distally fixated versus nondistally fixated leg extensor resistance training on knee pain in the early period after anterior cruciate ligament reconstruction. Phys. Ther. 82(1): 35–43.

Or This opinion from

Want to get Katrina Kaif’s sexy thighs? Try leg extensions!

A weight-training exercise, leg extensions target quadricep muscles that run along the front of your thigh from your knee to your pelvis and are responsible for hip flexion and knee extension. They are usually performed using a leg-extension machine, where you sit on a chair and lift a weight bar using your quadriceps muscle. When you perform leg extensions, you contract the quad to bring your knees up against the weighted resistance. While many other exercises such as squats, lunges or deadlifts also work on the quads, they do not isolate the muscle like a leg extension does.

Any exercise that requires you to contract your quadriceps against resistance can deliver the same effect as a leg extension machine. If you are doing it at home, you can use a chair and resistance bands or ankle weights. You can also mimic the exercise by walking backward on a treadmill or doing a reverse step up onto a slightly raised platform.

Five key benefits of leg extensions

  1. Leg extensions are a key exercise in strengthening the patellar ligament and quadriceps attachment for the knee. This exercise focuses on strengthening the quad alone and, therefore, strengthens key attachments for the knee joint at the same time.
  2. A machine-assisted training, it is a very good option for exercise beginners and you need not worry about form and posture.
  3. It is also a good finisher exercise, as it is an isolation exercise for quadriceps that can be performed after compound exercises like squats or dead lifts.
  4. You can focus on target muscles more selectively. While doing squats, you hit a lot of muscles at once and expend a lot of energy. With leg extensions, you focus just on quads.
  5. There is a common belief that leg extensions can be harmful for your knees. But in my opinion, it is a good exercise for people with knee problems as they are performed while seated, reducing the impact on the knee. However, it is advisable to reduce the weight load and focus on the squeeze instead. Also, if you are recovering from any leg injury, it is best to consult a doctor before embarking on this form of exercise.


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