The glute-ham raise (GHR) is one of the best exercises for your hamstrings, it provides you with the highest muscle activation compared to good morning and the leg curl.
Beside the hamstrings, This exercise will also strengthen the glutes, lower back, and the calves as secondary muscles. Though despite its name, the glute-ham raise does not target the glutes as much as it works on the hamstrings.
Working this muscles is very beneficial, These muscles tend to be neglected in many workout programs. Strengthening the hamstrings and the glutes will help your athletic ability, you'll be able to jump higher, and run faster. And it will also improve your ability performing other lower body lifts, like the deadlift and squat. It also unloads the spine, which is essential for long-term training health.
Another benefit is that the glute-ham raise puts little stress on your lower back, so it might be a good option for people who suffer from lower back pains.
The glute-ham raise is usually done with a dedicated GHR machine. But if you don't have one, the exercise can also be done by tucking your feet under a heavy object for balance. You can use a barbell or even a heavy furniture.
The only drawback is that with the floor variation, you won't work both knee flexion and hip extension at the same time. This only works your hamstrings doing knee flexion.
A down side of the glute-ham raise is that this is an advanced exercise that doesn't fit well for beginners. Most people do not have enough strength in their hamstrings and core to perform it correctly. You'll need to strengthen these muscles with other exercises before you can do the glute-ham raise.
The two most common mistakes are breaking at the hips and hyperextending through the lumbar spine, both of which come from not being strong enough in the hamstrings and glutes. Try to use a easier variation or use your arms to assist you to push yourself, just make sure that the pressure stays on the hamstrings for as long as possible, while your arms only assisting the movement.
Your back should be held straight on the same line as your thighs throughout the movement.
Avoid pointing your toes away from your body. Doing so will put too much stress on your calves.