What muscles does the side plank work?

The muscles down the side of your trunk, your obliques and the deeper muscle beside your lower spine, hold you against folding toward the floor. Your shoulder holds you up and your glutes are loaded far more than the listing suggests, particularly at the side of the bottom hip.

How long should you hold a side plank?

Until your hips start to drop or your body rotates, then stop. The exercise has a visible endpoint, which is more useful than a number, and holding past it trains a position you are no longer in.

Is the side plank good for the glutes?

Highest of what it has been compared against, in the leg-raised version. Across 18 rehabilitation exercises chosen to train the muscle at the side of the hip, that version produced the two highest readings, with the bottom leg highest of all. That is a ranking inside one tested set of exercises, not a claim about everything you could do instead.

Should my feet be stacked or one in front of the other?

Staggered is easier because it widens your base. Stacked is harder to balance and does not change which muscles are working. Use the version you can hold square.

Why is one side so much harder than the other?

Most people find one side easier and never notice, because nothing else in a training week asks you to compare. Do the harder side first and match the other to it. It is a piece of information, not a diagnosis.

How do I make side planks easier?

Come down onto your bottom knee with your top leg on the floor in front for balance. That shortens the body and cuts the load considerably, and the position you are learning is the same one.

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Bodyweight · beginner · waist

Side plank hold on elbow

Also called Side bridge, Elbow side plank, Lateral plank, Side plank.

The short answer

A side plank lies you on one side, props you on that forearm, and lifts your hips until your body is a straight line seen from the front. The muscles down the side of your trunk do the work, holding you against folding toward the floor. What almost nobody mentions is how much of this lands on the side of your hip: when a version of this exercise was measured against seventeen others chosen to train that muscle, it came out top, in both legs.

How to do it

Step oneLie on your side with your legs stacked and prop yourself up on your forearm, with your elbow directly beneath your shoulder.
Step twoLift your hips off the floor so your body forms a straight line from head to feet.
Step threeKeep your core engaged, your top hip pushed upward, and avoid letting your hips sag or rotate.
Step fourHold the position for the desired duration while breathing steadily.
Step fiveLower your hips, rest, and repeat on the other side.

What usually goes wrong

Each starts with what you would notice.

Your hips drift down toward the floor as the seconds pass.

WhyThe muscles down your side have stopped holding you level, so the line from your head to your feet has bent at the waist. There is much less to resist once the hip is low, which is why it feels survivable.

FixEnd the set when the line goes rather than riding it out. Then start the next one from your knees instead of your feet, which shortens the body and makes the line holdable again.

You end up half rolled toward the floor or half turned toward the ceiling.

WhyThe body has rotated, so gravity is no longer pulling you sideways and the muscles you set the exercise up for have less to do. It is the easiest thing to drift into because it is genuinely more comfortable.

FixStack your shoulders one directly above the other and your hips the same, and pick a point on the wall in front of you to face. Rotation is easy to see on a phone propped at the far end of the mat and almost impossible to feel.

Your bottom shoulder feels squashed and your ear is close to it.

WhyThe supporting shoulder blade has slid up toward your ear, so your torso is sinking down between your arm and the floor rather than being held up by it.

FixPush the floor away with your forearm until your bottom shoulder moves down away from your ear and your chest lifts. Keep the elbow directly under the shoulder. If the shoulder sinks again, the hold is done.

One side is much better than the other and you have never really noticed.

WhyThis is the only trunk exercise you do twice, once per side, and most people do the easier side first and match the harder one to it, or the other way around.

FixStart with the weaker side and hold the stronger one for the same length. That is not a diagnosis of anything, and it is a piece of information about yourself you cannot get from a front plank.

Plain hold or with the top leg lifted

Lifting the top leg into the air turns this from a trunk hold into something else entirely, and the numbers behind that are unusually clear.

26 people were tested across 18 rehabilitation exercises chosen to train the glutes, including the muscle at the side of the hip. The side plank with the top leg raised produced the two highest readings of the whole set: around 103 percent of a maximal contraction in the leg on the floor, and around 89 percent in the leg being lifted. A single leg squat came third.

The result that surprises people is which leg worked hardest. The bottom one, the one that looks like it is just lying there, was the highest of the eighteen.

Those numbers belong to the leg-lifted version, not to the plain hold described here. Treat the plain hold as the place to build the position, and the leg lift as the version that turns it into serious hip work.

Feet stacked or staggered

Stacking one foot exactly on top of the other gives you a base about as wide as one foot, which is very little to balance on.

Staggering them, top foot in front of the bottom one, widens that base considerably. Nothing about the muscles changes. What changes is how much of your attention goes on not tipping over, which for most people is the difference between holding a position and fighting one.

Start staggered and stack them later if you want the balance challenge back. The version you can hold with your hips up and your body square is worth more than the version you wobble through.

The muscle nobody mentions

The side plank is filed as an obliques exercise everywhere including here, and that is accurate as far as it goes. The part that gets left out is the hip.

The muscle at the side of your hip, gluteus medius, is what stops your pelvis dropping when you stand on one leg. In a side plank, the bottom leg is holding your whole body up on its side, and that muscle is under a very large demand. Researchers looking for the best way to train it found the leg-raised side plank at the top of a list of 18 exercises, above every band walk and clamshell in the set.

That is worth knowing because it changes what this exercise is for. It is more than the sideways version of a plank. It is one of the few movements that loads the trunk and the side of the hip in the same position, which is roughly the job both of them do when you walk.

The usual limits still apply. It trains muscles, and it does not promise anything about hips, knees, gait or pain, no matter how often it appears in rehabilitation programs. If something hurts and keeps hurting, that is a question for a physiotherapist.

What it is for

The side plank hold on elbow is a bodyweight isometric exercise targeting the obliques, with secondary engagement of the abs, shoulders, and glutes. It involves maintaining a rigid lateral body position on one forearm to build lateral core stability and resist spinal rotation.

Questions people ask

What muscles does the side plank work?: The muscles down the side of your trunk, your obliques and the deeper muscle beside your lower spine, hold you against folding toward the floor. Your shoulder holds you up and your glutes are loaded far more than the listing suggests, particularly at the side of the bottom hip.
How long should you hold a side plank?: Until your hips start to drop or your body rotates, then stop. The exercise has a visible endpoint, which is more useful than a number, and holding past it trains a position you are no longer in.
Is the side plank good for the glutes?: Highest of what it has been compared against, in the leg-raised version. Across 18 rehabilitation exercises chosen to train the muscle at the side of the hip, that version produced the two highest readings, with the bottom leg highest of all. That is a ranking inside one tested set of exercises, not a claim about everything you could do instead.
Should my feet be stacked or one in front of the other?: Staggered is easier because it widens your base. Stacked is harder to balance and does not change which muscles are working. Use the version you can hold square.
Why is one side so much harder than the other?: Most people find one side easier and never notice, because nothing else in a training week asks you to compare. Do the harder side first and match the other to it. It is a piece of information, not a diagnosis.
How do I make side planks easier?: Come down onto your bottom knee with your top leg on the floor in front for balance. That shortens the body and cuts the load considerably, and the position you are learning is the same one.