Seated Leg Extensions
Primary Muscle Group: Quadriceps
Secondary Muscle Group: Hamstrings
Equipment Needed: Leg Extension Machine
The Benefits of Seated Leg Extensions
The seated leg extension is an isolation exercise and one used to target the muscles of the quads.
This exercise can be particularly hard on the knees. So, for those with prior knee injuries, it may be beneficial to stick with other movements, preferably compound, to target your quads.
The leg extension is a great exercise for quad development and may be beneficial to include in your workout routines if your goals are more aesthetics-driven.
The leg extension can be utilized in both leg workouts and full body workouts.
If you are looking for other exercises that are the best for building muscle or wanting to lose body fat then you should check our Free Workout Plan or our Workout Plans With Coaching for professionally designed workout plans that have been proven to get results.
The Risks of doing Seated Leg Extensions
Typically, leg extensions should not be done excessively heavy due to the lack of hamstring co-contraction with the quads. When one occurs in isolation it could present an injury risk to the knee if done with excessive weight.


How To Do Seated Leg Extensions
1. Select the desired resistance on the weight stack and insert the pin.
2. Adjust the seat so that the knees are directly in line with the axis of the machine.
3. Sit down and position your shins behind the pad at the base of the machine.
4. Take a deep breath and extend your legs as you flex your quadriceps.
5. As you lock out the knees, exhale to complete the repetition.
6. Slowly lower your feet back to the starting position and repeat for the desired number of repetitions.
For Perfect Technique
Ensure the axis of rotation for the knee directly matches that of the machine. In other words, the point of rotation for the machine should be in line with your knee joint itself. If the knee is positioned too far in front or behind the axis of rotation, there will be excessive stress added to the joint which could cause significant injury.
Pointing the toes can help to enhance mind muscle connection so try a few different foot positions to see what works best for you.
Variations
Once you have mastered the Seated Leg Extensions exercise you can try alternative exercises that target similar muscle groups such as;
How To Do a Walking Lunge
1. Stand upright, feet together, and take a controlled step forward with your right leg, lowering your hips toward the floor by bending both knees to 90-degree angles.
2. The back knee should point toward but not touch the ground, and your front knee should be directly over the ankle.
3. Press your right heel into the ground, and push off with your left foot to bring your left leg forward, stepping with control into a lunge on the other side. This completes two reps.
How To Do Leg Press
1. Load the machine with the desired weight and take a seat.
2. Sit down and position your feet on the sled with a shoulder width stance.
3. Take a deep breath, extend your legs, and unlock the safeties.
4. Lower the weight under control until the legs are roughly 45 degrees or slightly below.
5. Drive the weight back to the starting position by extending the knees but don’t forcefully lockout.
6. Repeat for the desired number of repetitions.
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