Weighted Seated Single Leg Knee Extension (VERSION 2)

How to do the Weighted Seated Single Leg Knee Extension (VERSION 2)

1. 1Sit upright on a sturdy bench or chair with your hips fully back and your feet flat on the floor, hip-width apart.
2. 2Secure an ankle weight around the ankle of your working leg, or hook a light weight plate over the top of your foot as an alternative load.
3. 3Shift slightly so the working leg hangs freely from the edge of the bench without the back of your knee pressing hard against the edge.
4. 4Brace your core and place both hands on the sides of the bench for stability.
5. 5Slowly extend your working knee until your leg is straight and parallel to the floor, squeezing your quadriceps at the top.
6. 6Hold the extended position for a one-count, keeping your toes pointed up or slightly toward you.
7. 7Lower your foot back toward the floor in a controlled manner, stopping just before your foot touches down.
8. 8Complete all reps on one side, then switch to the other leg.

Form tips

• Keep your thigh pressed lightly against the bench throughout the movement so the work stays in the quadriceps rather than the hip flexors.
• Move at a slow, deliberate tempo — roughly two seconds up and three seconds down — to maximize time under tension and reduce momentum.
• Avoid rocking your torso backward as the weight gets heavy; if you cannot keep your back upright, reduce the load.
• Start with a lighter ankle weight than you think you need; the lever arm of a fully extended leg makes even modest loads demanding.

Common mistakes

• Using momentum to swing the leg up instead of contracting the quad, which reduces muscle activation and can strain the knee joint.
• Letting the knee drift inward or outward during extension, which places uneven stress on the knee and reduces efficiency.
• Hyperextending the knee at lockout by locking it forcefully, which compresses the joint unnecessarily — stop just short of full lock.
• Allowing the working thigh to lift off the bench during the extension, which recruits the hip flexors and reduces isolation of the quadriceps.
• Choosing too much weight too soon, causing the torso to lean back and shift load away from the quadriceps.

Frequently asked questions