What Muscle Does the Incline Leg Press Work?

The incline leg press is known by many names, including the hip sled and the 45-degree leg press. It works by loading weight onto the foot platform, which you sit below as you exercise, drawing the weight down by bending your knees and pushing it back up. Using weight plates for resistance allows you to load it up as light or as heavy as you like to work your quadriceps.

Although the incline leg press was designed to work your quadriceps, it calls upon your glutes, adductors and even the soleus muscles in your calf muscles as assisting muscles. Your hamstrings and even the medial heads of your calf muscles help stabilize your hip and knee joints as you work through the move, making it a compound exercise.

Using incline leg presses to strengthen your quadriceps provides the bonus of developing knee support. In his book, "Lee Haney's Ultimate Bodybuilding," Haney recommends incline leg presses to prepare your knees to manage heavy squats. The leg press is essentially a reverse squat with the resistance load being entirely on your legs and not on your lower back. As a result, it is effective for getting the benefits of a squat for your quadriceps without stressing your back.

If you really want to work on emphasizing the negative motion of the incline leg press for added benefit to your quadriceps, try doing it one leg at a time. When you press with both legs, they help each other through the exercise, but when you work a single leg, each leg will get the full effect of the resistance. You'll also be able to concentrate more effectively on executing the movement correctly, focusing on the contraction of the muscle as you press and come back down. It's a more intense variation of the exercise, but one that will allow you to pinpoint problems if one leg is stronger than the other as well as ensuring proper form.

Maintaining proper technique at all times can mean the difference between a productive workout and one that ends in injury. To avoid hurting yourself when working on the incline leg press, keep your knees facing the same direction as your toes, and keep your feet flat on the foot plate at all times during the exercise. You might want to lift your heels, but you should focus on maintaining full contact with the foot plate. When your legs are extended at the top of the move, don't lock your knees. As you lower the weight back down, maintain control of the movement, lowering the weight slowly and not allowing your quadriceps to touch your torso.