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  3. Exercises
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  5. Legs
  6. /
  7. Lever One Leg Extension

Exercise guide

Lever One Leg Extension

  • Intermediate
  • Isolation
  • Rep-based
  • Lower legs
  • Upper legs

This unilateral isolation exercise targets the quadriceps, allowing you to focus on each leg individually to correct muscle imbalances and maximize peak contraction. It is highly effective for building definition and strength in the front of the thigh by removing the ability for a stronger leg to compensate.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Lever One Leg Extension demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Quadriceps

Equipment

  • Leverage machine

Setup

  1. Adjust the seat back so that your knee joint aligns perfectly with the machine's pivot point (axis of rotation).
  2. Position the lower leg pad so it rests comfortably just above your ankle on the working leg.
  3. Sit back firmly against the backrest and grasp the side handles to stabilize your torso.
  4. Place your non-working foot flat on the floor or the machine's designated footrest.

How to do it

  1. Exhale as you extend your leg upward in a controlled arc until your knee is fully straight.
  2. Squeeze your quadriceps hard at the top of the movement for a one-second pause.
  3. Inhale as you slowly lower the weight back to the starting position using a controlled 3-second tempo.
  4. Maintain tension on the muscle by stopping just before the weight stack touches down between reps.

Form checklist

  • Keep your lower back and hips pressed firmly against the seat throughout the set.
  • Ensure your toes are pointing straight up or slightly outward to maintain alignment.
  • Avoid using momentum or 'kicking' the weight; the movement should be smooth and deliberate.
  • Do not allow your working hip to hike up or rotate during the extension.

Pro tips

  • Pull yourself down into the seat using the handles to create a more stable base, which allows for greater force production in the quad.
  • Focus on the mind-muscle connection by visualizing the quadriceps shortening as you lift the lever.

Make it harder

  • Add a 3-second isometric hold at the point of peak contraction on every rep.
  • Implement a 'slow eccentric' by taking 5 seconds to lower the weight, increasing time under tension.

Frequently asked

What muscles does the lever one leg extension work?
The lever one leg extension primarily targets the quadriceps.
What equipment do you need for the lever one leg extension?
The lever one leg extension uses leverage machine.
Is the lever one leg extension good for beginners?
The lever one leg extension is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 3 Point Standing HopsIntermediate · calves, glutes, hamstrings, and quadriceps
  • 4 Cone Single Foot Lateral HopsIntermediate · calves, glutes, hamstrings, and quadriceps
  • 4 Way Single Leg HopAdvanced · calves, glutes, hamstrings, and quadriceps
  • 90 To 90Beginner · abs, glutes, obliques, and quadriceps

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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