How to Do a Leg Extension

Leg extensions are known as an open chain kinetic exercise that targets the quadriceps of the upper legs. The standard exercise requires the use of a machine but can be modified for those without access to a gym or equipment.

The quadriceps assist in the straightening motion of the knee, so strengthening the quads can assist in daily activities such as walking and squatting down to pick up items. Stronger quads will also help to improve overall posture.

How To

  • Before beginning the exercise, you’ll need to adjust the machine. The bottom of the pad should sit just above the ankles on your lower legs, and your knees should be at about 90 degrees.
  • Sit up straight and grip the handles at your sides. Exhale as you press your legs upward until they are almost fully extended. Make sure not to lock your knees at the top of the movement.
  • Take a breath in and exhale as you slowly lower your legs back down. Keep your back pressed into the backrest, but make sure not to arch your back.


Three sets of 8–12 repetitions with a moderate load is the most you should aim for when using a leg extension machine. This is not the exercise for achieving endurance, nor is it for attempting maximum lift.


Body weight: If you’re recovering from an injury or are concerned about straining your knees, leg extensions can be performed without any additional weight. Seated on a chair or bench, you would slowly lift and lower the leg as you would during a normal leg extension, using the weight of your own leg to work the muscles. Make sure not to slouch during the exercise.

Resistance band: If you don’t have access to a machine, you can perform leg extensions using a tension band. This will be done one leg at a time and requires a sturdy chair. Place the tension band around the back of the leg you are working.

Weighted: Another seated option that doesn’t require a machine is to use ankle weights. Start with 5lbs and increase to no more than 10lbs as you get stronger. It can help to grip the edge of your chair and press your back into the back rest.

Standing leg extension: This exercise can also be done standing and one leg at a time. You’ll need a sturdy piece of furniture to attach the band to, and it might help to have a chair or railing to hold for balance. You’ll stand with your foot extended behind you with your knee bent and then slowly extend your foot out toward the front.

Cautionary Notes

Attempting to lift maximum loads performing leg extensions are almost guaranteed to cause knee ligament strain and should be avoided.

Make sure not to lock the knees at the top of the movement. This can strain the knee joint.

Perform the movements slowly. Quick, jerky movements or using momentum will only take away from the intended benefit of the exercise.

If you are recovering from a knee, ankle or thigh injury, consult your doctor or a fitness trainer before attempting the maneuver.

More Leg Extension Related Resources

Leg Extension Alternatives: 8 Exercises, Benefits, and More
How to Do Leg Extensions: Techniques, Benefits, Variations
Your Definitive Guide to Leg Extensions
Leg Extension – Sworkit | At Home Workout and Fitness Plans
How to Do Leg Extensions: Techniques, Benefits, Variations
Your Definitive Guide to Leg Extensions
Leg Extension – Sworkit | At Home Workout and Fitness Plans

Related Videos