How to do a Single Leg Leg Extension
Reviewed by Jim Parker, CPT, B.A. Kinesiology
About this exercise
- Sets Logged
- 750,466
- Popularity Rank
- 189th
- Difficulty
- Beginner
- Quads Strength
- 94 mSCORE 21st
- Equipment Required
Leg Extension Machine
Workouts with Single Leg Leg Extension
Target muscles worked
Instructions for Proper Form
Single Leg Leg Extensions is a variation of Leg Extensions that uses one leg at a time. Like other leg extensions, this isolation exercise targets your quadriceps. By targeting one leg at a time, you can focus your attention on getting good muscle activation in each leg. In addition, this can help you identify and address strength imbalances between legs. While leg extensions can be a great way to build strength and muscle mass in your quadriceps, they can also place a lot of tension on your knees.
- Sit upright in a single leg extension machine while placing the lower pad just above your ankles in front of your lower legs.
- Your knees should be flexed to 90 degrees and the back pad should be contact with your lower back and shoulders.
- Grab ahold of the handles for additional support.
- Extend your left leg in an upward arc until your lower leg is aligned with your thighs.
- Return to the starting position and repeat with the opposite side.
Common Form Mistakes
Too Much Weight
This exercise inherently places a lot of tension on your knee. Adding too much further increases your risk of injury. You can do this exercise safely by focusing on controlling the movement, and limiting your range of motion prior to fully extending your leg.
High Resistance
Extending your arms away from your body increases the tension placed on your joint’s and muscles. Keep the resistance for this exercise fairly light, and focus on moving slowly, and controlling the movement before you add more resistance.
Weight & 1 Rep Max Calculator
Average Single Leg Leg Extension standards by male, female, weight, age and height
Use this calculator to see Fitbod's possible first recommendations for you. This would be your starting line, based on more than 4.5 billion logged sets from 1.1 million users.
- beginner8reps25lbs1 Rep Max30lbs
- intermediate8reps35lbs45lbs
- advanced8reps45lbs55lbs
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Alternatives & Variations to Single Leg Leg Extension
1. Leg Extension
99.4 mSCORESWAPPED 4,617 TIMESLeg Extensions are an isolation exercise that target the quads. Due to a severe lack of isolation movements for the lower body, this is a great option for specifically targeting your quadriceps. The use of a machine restricts your range of motion, and adds some stability to the movement. This can help your focus more on exertion than stabilizing the movement. The downside to this exercise is that it places a lot of tension on your knee. Keep your weights light, and focus on pausing near the end of your range of motion.
2. Machine Leg Press
95.1 mSCORESWAPPED 473 TIMESMachine Leg Press is a variation on the more standard Leg Press. Like the Leg Press, this is a compound exercise that primarily recruits the quadriceps. This is a great exercise for building strength and muscle mass in your quads. The use of a machine doesn’t change anything significant about this exercise, although your positioning may change depending on the machine you’re using.
3. Leg Press
99.7 mSCORESWAPPED 403 TIMESLeg Press is a compound exercise that primarily targets the quadriceps. The exercise itself is fairly similar to a standard squat, with some key differences. The biggest of these differences is the added stability from supporting your back on the Leg Press Machine. The end result of these changes is a more stable movement that further emphasizes your quadriceps. Leg Press is an excellent exercise for anyone looking to build muscle mass or strength in their quads.
4. Dumbbell Lunge
97.6 mSCORESWAPPED 168 TIMESDumbbell Lunge is a variation on the more standard Lunge. Similar to other Lunge variations, Dumbbell Lunge is a compound exercise that primarily targets the quads. The exercise itself is the same as a standard lunge except for the added weight from holding dumbbells in each hand. This is a great variation for anyone looking to make their lunges a bit more challenging without adding more complexity to the movement.
5. Seated Leg Curl
98.8 mSCORESWAPPED 152 TIMESSeated Leg Curl is a weighted, isolation exercise that targets the hamstrings. Because a vast majority of lower body exercises tend to be compound movements, this exercise is a great way to isolate the hamstrings for building muscle mass, and developing strength. The use of a machine restricts your range of motion, and adds stability, allowing you to focus on exertion more than stabilizing the movement.
- Beginner
- Hamstrings
- Leg Curl Machine
6. Dumbbell Bulgarian Split Squat
91.4 mSCORESWAPPED 150 TIMESDumbbell Bulgarian Split Squat is a weighted variation of a Bulgarian Split Squat. Like other Bulgarian Split Squats, this exercise is a compound movement that primarily targets your quads. The use of dumbbells allows you to add more resistance to this exercise, without restricting your range of motion and posture as much as using a barbell.
7. Single Leg Leg Extension
60.6 mSCORESWAPPED 145 TIMESSingle Leg Leg Extensions is a variation of Leg Extensions that uses one leg at a time. Like other leg extensions, this isolation exercise targets your quadriceps. By targeting one leg at a time, you can focus your attention on getting good muscle activation in each leg. In addition, this can help you identify and address strength imbalances between legs. While leg extensions can be a great way to build strength and muscle mass in your quadriceps, they can also place a lot of tension on your knees.
8. Dumbbell Goblet Squat
87.9 mSCORESWAPPED 143 TIMESDumbbell Goblet Squat is a variation on the more standard Front Squat. Like other squat variations, this compound exercise primarily targets the quadriceps. Goblet squats are beneficial because they require less upper body mobility in order to keep the weight in the proper position compared to using a barbell.
9. Hack Squat
90.1 mSCORESWAPPED 136 TIMESHack Squat is a variation of squats that utilizes a specific machine to add resistance. Like other squat variations, this exercise primarily targets your quads. The use of a machine can assist you by redistricting your range of motion more than with the use of free weights, as well as adds more stability to the movement.