What muscles do hyperextensions work?

In the version described here, the muscles running either side of your spine do the work, with your glutes and hamstrings assisting. If you keep your back rigid and fold only at the hips instead, the glutes and hamstrings become the movers and your back muscles just hold.

How far up should you go on a back extension?

To a straight line from your heels through your head, then stop. Despite the name, going past that point is not part of the movement as described here, and the extra arch tends to come from a swing rather than from the muscles.

Are hyperextensions good for lower back pain?

We will not answer that, because we cannot. The exercise trains the muscles that extend your spine. Whether it helps, harms or does nothing for any particular back is a question for a physiotherapist who can see you.

Should I round my back or keep it flat?

Both are real exercises and they are different. Rounding and extending trains the spinal muscles. Staying flat and hinging at the hip trains the glutes and hamstrings. Pick one per set rather than sliding between them.

Is a 45 degree bench better than a flat one?

It is friendlier, not better. The flat bench makes the top of the rep the hardest point, since your torso is horizontal exactly where you finish. The angled bench moves the hard part lower and lets most people work through more range.

Do I need my hips strapped down?

The evidence is mixed, which is not the answer most pages give. One study of this exercise found greater activity in the spinal muscles with the pelvis free, while other work found more activity in the deeper spinal muscles with it stabilized. Use what the bench gives you.

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Bodyweight · beginner · back

Hyperextensions

Also called Back extension, Roman chair back extension, 45 degree back extension, 45-degree hyperextension.

The short answer

A hyperextension lies you face down on a bench with your hips at the edge of the pad and your feet held, lowers your torso toward the floor, and raises it back to a straight line. The muscles running either side of your spine do the work in the version described here, because the movement bends and straightens at the waist. Your glutes and hamstrings assist. There is a second way to do this exercise on the same bench that trains different muscles entirely, which is the thing worth knowing before your next set.

How to do it

Step onePosition yourself face down on a hyperextension bench with your hips at the edge of the pad and feet secured.
Step twoHold the handles at the front of the bench, cross your arms over your chest, or place your hands behind your head.
Step threeLower your torso toward the floor in a controlled manner, bending at the waist.
Step fourRaise your torso back up by contracting your lower back and glutes until your body forms a straight line.
Step fivePause at the top.

What usually goes wrong

Each starts with what you would notice.

You swing up at the top and arch hard past a straight line.

WhyThe name of the exercise invites it, and the top is where the movement feels easiest, so the last part of each rep turns into a throw rather than a lift.

FixStop at the point where your body makes one line from heels to head, and hold it for a beat before lowering. The straight line is where the catalog steps end the rep, and it is a position you can check rather than a feeling you have to judge.

Your neck aches and your hands are behind your head.

WhyThe hands have started pulling on the back of your skull to help the torso rise, so the effort is arriving at the top of your spine instead of the bottom.

FixCross your arms over your chest instead. It is the easier hand position and it removes the option. The demonstration keeps both hands on the bench handles for every rep, which is the other place help can come from, so if you hold them let them steady you rather than push. Once the movement runs without any help from your arms, hands behind the head becomes a way to make it harder rather than a way to cheat.

You cannot get much range and it feels like your hips are jammed.

WhyThe pad is set over your hip joint rather than just below it, so your body cannot fold at the hip and the range has to come from somewhere higher up your back.

FixLower the pad until its top edge sits at the crease of your hip with your hip bones just clear of it. If the bench does not adjust, that bench will not fit everyone, and it is the equipment rather than you.

The reps get faster and you bounce out of the bottom.

WhyDropping quickly builds momentum at the bottom that carries you back up, so the muscles you came for miss the hardest part of the rep.

FixTake two seconds down, pause at the bottom with no tension in the swing, then rise. Fewer reps done this way is a longer set than it sounds.

Two exercises, one bench

The same machine gives you a spinal exercise or a hip exercise depending on one decision, and nobody tells you that you are making it.

Keep your back flat and rigid and fold only at the hip, and your glutes and hamstrings produce the movement while the muscles along your spine hold a position without changing length. That is a hip extension exercise with an isometric back.

Let your spine round on the way down and extend on the way up, which is what the steps here describe, and the muscles running either side of your spine are the ones doing it. That is a back exercise.

Both are legitimate. What causes trouble is doing the second while believing you are doing the first, or drifting between them across a set. Decide which one you came for, then hold that decision for the whole set.

45 degree bench or flat bench

The two common benches put you at different angles and the difference is about where the exercise is hardest, not about which muscles it trains.

On a flat bench, your torso is horizontal at the top of the rep, so gravity is pulling hardest exactly where you finish. The top is the hard part and the bottom is comparatively easy.

On a 45 degree bench, the hardest point comes lower in the range and the top of the rep is easier, which lets most people work through more range before the position collapses.

If you have a choice, the angled bench is the friendlier place to learn the movement. If your gym has one bench, that is the bench, and the exercise still works.

What it can honestly claim

This is the exercise most likely to be sold as a cure, so it is worth being careful about what the evidence supports.

It trains the muscles that extend your spine, and it does so at high levels: in one study of isometric back-extension exercises in 18 healthy people, the muscles either side of the spine and the deeper layer underneath them were both recruited at around 76 to 79 percent, working together rather than taking turns. If your goal is to train those muscles, this exercise trains them.

What it cannot claim is anything about back pain. We do not know whether it prevents it, causes it or is irrelevant to it in any individual, and a website that has never seen you is not in a position to say. If something hurts and keeps hurting, that is a question for a physiotherapist.

One more honest note. The straps and pads that hold your pelvis down are usually described as essential for making the exercise work. The research on that is genuinely split: one study of this exact movement found more activity in the spinal muscles with the pelvis free, even though the people doing it reported feeling it more in the back when the pelvis was held. Others found the opposite for the deeper spinal muscles. Nobody should be telling you this is settled.

What it is for

Hyperextensions, or back extensions, are a bodyweight exercise targeting the lower back. Performed on a hyperextension bench, this movement isolates and strengthens the erector spinae muscles, improving spinal stability and posterior chain endurance.

Questions people ask

What muscles do hyperextensions work?: In the version described here, the muscles running either side of your spine do the work, with your glutes and hamstrings assisting. If you keep your back rigid and fold only at the hips instead, the glutes and hamstrings become the movers and your back muscles just hold.
How far up should you go on a back extension?: To a straight line from your heels through your head, then stop. Despite the name, going past that point is not part of the movement as described here, and the extra arch tends to come from a swing rather than from the muscles.
Are hyperextensions good for lower back pain?: We will not answer that, because we cannot. The exercise trains the muscles that extend your spine. Whether it helps, harms or does nothing for any particular back is a question for a physiotherapist who can see you.
Should I round my back or keep it flat?: Both are real exercises and they are different. Rounding and extending trains the spinal muscles. Staying flat and hinging at the hip trains the glutes and hamstrings. Pick one per set rather than sliding between them.
Is a 45 degree bench better than a flat one?: It is friendlier, not better. The flat bench makes the top of the rep the hardest point, since your torso is horizontal exactly where you finish. The angled bench moves the hard part lower and lets most people work through more range.
Do I need my hips strapped down?: The evidence is mixed, which is not the answer most pages give. One study of this exercise found greater activity in the spinal muscles with the pelvis free, while other work found more activity in the deeper spinal muscles with it stabilized. Use what the bench gives you.