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.

Sit on a chair with your back straight and your feet hip-width apart. Extend on the knee until you fully extend your legs, hold it for a couple of seconds, and go back to the starting position. Repeat on the same side and finish one set before swapping.

For a seated leg extension with ankle weights, start with 5-pound weights and progress only to 10-pound weights. Or, loop a resistance band around your ankle and around the rear leg of the chair on the same side. Sit in a chair with your back straight. Lift one leg straight out from your body. Hold for five seconds. Lower to starting position.

Sit down on the seat. Adjust the backrest/seat and leg pad to fit your size (see above). Choose a weight that you can move 12 to 20 times. Press your butt into the seat by firmly grabbing the handles on the sides with your hands. Now, move your lower legs upwards by extending your knees. Perform the movement smoothly and without swinging.

Adjust the machine to your height. Select a weight that is challenging but allows you to complete all sets and reps. Sit on the machine with your back against the padded seat. Your feet should be placed under the padded lever. Hold onto the handles for support. Extend one leg until it is straight.