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Exercise Guide

How to do one leg extension

Master the setup, range of motion, and tempo for safer, more effective reps.

The one-leg extension is a unilateral isolation exercise that primarily targets the quadriceps muscles. By working one leg at a time, you can effectively address muscle imbalances and ensure equal strength development across both limbs. This movement is performed on a leg extension machine and is highly effective for isolating the front of the thigh without engaging the glutes or hamstrings.

Stats

TIER
1
DIFFICULTY
Intermediate to Advanced
EQUIPMENT
Leg Extension
TARGET MUSCLES
Quads

Instructions for Proper Form

Setup:

  1. Machine Adjustment: Adjust the seat back and foot pad on the leg extension machine so that your knee aligns with the machine's axis.
  2. Starting Position: Sit with your back against the backrest and one foot positioned behind the padded lever. Your knee should be bent at a 90-degree angle. Your other leg can either rest on the floor or be crossed over the working leg.

The Lift:

  1. Extend the Leg: Exhale and extend your knee, lifting the lever until your leg is almost straight. Avoid locking out your knee at the top.
  2. Hold and Squeeze: Pause briefly at the top of the movement, squeezing your quadriceps muscles.
  3. Controlled Lowering: Inhale and slowly lower the weight back to the starting position, resisting the weight as it comes down.
  4. Repeat: Perform the desired number of repetitions, then switch legs.

Tips:

  • Focus on the Quadriceps: Concentrate on the feeling of your quadriceps muscle working throughout the movement.
  • Maintain Back Contact: Keep your back pressed firmly against the backrest throughout the exercise.
  • Smooth Movement: Avoid jerking or bouncing the weight. The movement should be smooth and controlled.

Common mistakes: Lifting the hips off the seat to leverage more weight, locking the knee too forcefully at the top, and using momentum rather than muscle contraction.

Alternatives

Leg Extension

one leg extension

Quads
Leg Extension

leg extension

QuadsGlutes
Barbell

barbell squat

QuadsGlutes
Leg Press

seated leg press

QuadsGlutes
Squat Rack

barbell front squat

QuadsGlutes
Bench

barbell bulgarian split squat

QuadsGlutes
Barbell

barbell box squat

QuadsGlutes
Hack Squat Machine

hack squat

QuadsGlutes
None

forward lunge

Quads
Kettlebell

kettlebell front squat

QuadsGlutes
Kettlebell

kettlebell goblet squat

QuadsGlutes
None

rear lunge

QuadsGlutes
Kettlebell

kettlebell one arm swing

QuadsGlutes+2
Kettlebell

kettlebell thruster

QuadsGlutes+5
Barbell

barbell overhead squat

QuadsGlutes
Barbell

barbell zercher squat

QuadsGlutes
Barbell

barbell overhead lunge

QuadsGlutes+1
Leg Press

squat calf raise on legpress

QuadsGlutes+1
None

step up with chair

QuadsGlutes+1
Dumbbell

dumbbell swing

QuadsHamstrings+3
Dumbbell

dumbbell thruster

QuadsGlutes+4
Smith Machine

smith-machine leg press

QuadsGlutes
Bench

sissy squat

QuadsGlutes
Smith Machine

smit-machine split squat

QuadsGlutes
Hack Squat Machine

reverse hack squat

QuadsGlutes
Smith Machine

smit-machine squat

QuadsGlutes
Dumbbell

dumbbell lunge

QuadsGlutes
Pendulum Squat Machine

pendulum squat

QuadsGlutes
None

pistol squat

QuadsGlutes
Sled Leg Press

sled 45° leg press

QuadsGlutes
Tread Mill

run on treadmill

QuadsGlutes+1
None

run

QuadsGlutes+1
Assault Runner

assault run

QuadsHamstrings+2
Ski Trainer

ski trainer

QuadsGlutes+3
Barbell

barbell thruster

QuadsGlutes+4
Assault Bike

assault bike run

QuadsHamstrings+6