Leg extensions are exercises usually done with a lever machine. You sit on a padded seat and raise a padded bar with your legs. The exercise works mainly the quadriceps muscles of the front of the thigh—the rectus femoris and the vastus muscles. You can use this exercise to build lower body strength and muscle definition as part of a strength training workout.
XQS Leg extension
Set up the leg extension machine so the pad is at the top of your lower legs at the ankles. Your knees are at 90 degrees. Select a weight that will give you a moderate load for 10 to 12 repetitions.
● Place your hands on the hand bars.
● Lift the weight while exhaling until your legs are almost straight. Do not lock your knees. Keep your back against the backrest and do not arch your back.
● Exhale and lower the weight back to starting position.
● Do three sets of eight to 12 repetitions.
For a standing leg extension using a resistance band, you would anchor on end of the band behind you and loop the band around your ankle. Stand in a position where the band has no tension when your knee is bent with ankle behind you. Hold a rail or chair for balance as needed.
● Slowly straighten your knee to bring to the band under tension, maintaining a straight back.
● Extend as far as comfortable. Pause and slowly return to the starting position.
● Perform 10 repetitions, then do the same with the other leg.
Rather than using a leg extension machine, you can do leg extensions using ankle weights or resistance bands.
For a seated leg extension with ankle weights, start with 5-pound weights and progress only to 10-pound weights. Or, loop a resistance band around your ankle and around the rear leg of the chair on the same side.
● Sit in a chair with your back straight.
● Lift one leg to straight out from your body.
● Hold for five seconds.
● Lower to starting position.
● Repeat with the other leg.
The leg extension targets the quadriceps, the large muscles of the front of the thigh. This is an "open chain kinetic" exercise, which is different from a "closed chain kinetic exercise," such as a squat.
The difference is that in the squat, the body part you're exercising is anchored (feet on the ground), while in the leg extension, you're moving the padded bar, which means your legs aren't stationary as they work, and thus the chain of movement is open in the leg extension.
The quads are well-developed in cycling, but if your cardio is running or walking, you mainly exercise the hamstrings at the back of the thigh. In this case, you may want to develop the quads to be more in balance. Building your quads can also increase the force of kicking movements, which can be beneficial in sports such as soccer or martial arts.
Stop this exercise if you experience any pain in your knee or ankle. Be sure to follow proper form when doing leg extensions and mix up your quadriceps workout.
