- Select your desired weight on the weight stack and insert the pin. A good weight to start with for beginners is five pounds. If you're more advanced, try 10 to 17.5 pounds.
- Start in a seated position on the machine with your back flat against the backrest and your legs underneath the pad. Make any necessary adjustments to the pad so that it's right above your ankle.
- With only your left leg, use your quadriceps to extend your leg until it's straight. (Your right leg should remain relaxed, hanging off the seat.) Hold for one second.
- Slowly lower back down to your start position. That's one rep.
- Do three sets of eight reps with each leg.
*To modify this exercise, extend both legs at the same time and increase the weight to 20 to 30 pounds.
