Single-Leg Leg Extension
A machine leg extension performed one leg at a time to isolate the quads and address strength differences between sides. It suits beginners wanting a focused, single leg quad exercise.
How to do the single-leg leg extension
- Sit in the leg extension machine and adjust the pad against the lower part of one shin.
- Line up the machine's pivot point with your knee and choose an appropriate weight.
- Rest your other foot on the floor or a footrest as your starting position.
- Extend the working leg fully, pausing briefly at the top of the motion.
- Lower back down slowly without letting the weight stack rest between reps.
- Complete your reps on one leg, then switch and repeat with the other leg.
Original library instructions (4 steps)
- Seat yourself in the machine and adjust it so that you are positioned properly. The pad should be against the lower part of the shin but not in contact with the ankle. Adjust the seat so that the pivot point is in line with your knee. Select a weight appropriate for your abilities.
- Maintaining good posture, fully extend one leg, pausing at the top of the motion.
- Return to the starting position without letting the weight stop, keeping tension on the muscle.
- Repeat for the desired number of repetitions.
Common mistakes
- Letting the weight stack touch down between reps; keep tension on the muscle throughout the set.
- Using momentum to kick the weight up; extend the leg with a smooth, controlled motion.
- Skipping the weaker leg or doing uneven reps; match the sets and reps on both sides.
- Locking the knee out forcefully at the top; extend fully but without slamming into lockout.
Sets and reps by goal
| Goal | Sets, reps and rest |
|---|---|
| Strength | 3 sets of 8 to 10 reps per leg, 60 to 90 seconds rest |
| Muscle | 3 to 4 sets of 10 to 12 reps per leg, 45 to 60 seconds rest |
| Endurance | 2 to 3 sets of 15 to 20 reps per leg, 30 seconds rest |
Ranges, not prescriptions. Start at the low end and add a set or a rep when every set feels controlled.
Tips
- Start with your weaker leg first so both sides get full effort while you are freshest.
In the app: this exercise is one of 873 in GymPilot's library, with the same photos, form cues and a link back to the moment in an imported video it came from.
Questions
Is the single leg leg extension good for beginners?
Yes. The machine supports your body and guides the movement, so beginners can focus on one leg at a time without worrying about balance.
What muscles does the single leg leg extension work?
It isolates the quads, training each leg through a full knee extension against the machine's resistance.
