Learn more about the benefits of the clamshell exercise — plus form tips from the move's biggest fan, Peloton instructor Selena Samuela.
Advertisement
Fitness woman doing clamshell exercise for glutes with resistance band
Credit: Getty Images

In a world of Instagrammable workouts, effectiveness can sometimes be mistakenly measured in sweaty selfies and the number of burpees completed. But some of the subtlest exercises can contribute to a well-rounded fitness routine in addition to more showy moves. One such underrated but indispensable move is the classic, butt-burning clamshell.

What Is the Clamshell Exercise?

"Clamshells are a move you learn about pretty immediately when getting into fitness," says Peloton instructor Selena Samuela, who might just be the maneuver's biggest advocate. "And every fitness professional has used them. You might have seen them performed in physical therapy as well, as they're a go-to for folks with lower back pain, folks looking for hip strengthening, and injury treatment and prevention."

Here's how the basic clamshell works: you lie on your side with your knees bent, raising and lowering your top knee while engaging your core and glutes. Yes, your legs are the "shells" in this analogy.

Samuela is such a big believer in the clamshell that she integrates the move into the vast majority of her lower body-focused Peloton classes. "Clamshells primarily work your gluteus medius — the part that forms the outer booty," she explains. "Strengthening that part of your body is so important no matter what you do in life, but especially if you're active or an athlete." It helps stabilize your pelvis any time you are walking or when you fall off balance. (Related: The Best Butt Workout Moves of All Time, According to Trainers)

How to Do the Classic Clamshell Exercise and Variations

For an exercise so potent, clamshells look deceptively simple. After all, you're lying down when you perform them. But don't be fooled by the setup. Stick with Samuela's instructions and your glutes will be screaming in no time.

How to Do the Basic Clamshell Exercise

Clamshell Exercise
Credit: Peloton

A. Start by lying on side with legs bent at a 45-degree angle and feet, ankles, knees, and hips stacked on top of each other. Allow bottom forearm to rest on the ground.

B. Engage core and glutes. Keeping feet together, lift upper knee up as high as possible without rocking or shifting hips and/or pelvis.

C. Lower top knee to return to start.

How to Do Variations On the Clamshell Exercise

The move is plenty tough all on its own, but if you've managed to master the stripped-down version, you can start to spice things up with modifications and advanced add-ons.

"To progress a clamshell, add a hip raise," says Samuela. "When you add a hip raise for a bridging clamshell, you're also demanding so much more from your core; it's essentially adding a side plank to the move." What's more, the variation also promotes shoulder stability and activates your triceps, she adds. Ready to ramp it up? Here's how to do a variation on the clamshell exercise:

A. Start by lying on side with legs bent at a 45-degree angle and feet, ankles, knees, and hips stacked on top of each other. Allow bottom forearm to rest on the ground.

B. Engage core and glutes. Keeping feet together, lift upper knee up as high as possible while simultaneously raising bottom hip off of the ground.

C. Lower top knee and bottom hip to return to start.

Clamshell Exercise
Credit: Peloton

You also have the option to add a dumbbell with or without the hip raise, says Samuela. To perform this one, simply hold a light dumbbell in your upper hand and rest it gently against your outer hip while performing the move.

"You can start with a relatively light weight if you're using a dumbbell and work your way up as you become more comfortable adding load to the move," she says. "Resistance bands are also awesome."

woman doing clamshell exercise
Credit: Peloton

Benefits of the Clamshell Exercise

To appreciate the clamshell's magic, it's important to understand the anatomy of your backside. Your butt muscles include three major players: the gluteus minimus and gluteus medius — which move your legs away from the center of your body, rotate your legs inward, and stabilize your pelvis — and the gluteus maximus — the biggest muscle in your body and the one that extends your hips and rotates your legs outward. The glute max is the most superficial of these muscles, sitting at the surface of the butt, starting at the hip bone and stretching downward to the thigh bone. The glute med is situated underneath the glute max, and the glute min sits below that as the smallest and deepest of the three, as Shape previously reported.

"Clamshells force you to engage both your glute medius and maximus," says Samuela. "If you're trying to make progress towards lower body gains, squats and deadlifts are probably the exercises you turn to first. But have you ever gone through a workout with a ton of squats and all you're feeling is a heavy quad burn? That's because you're likely not engaging your glutes properly."

Clamshell exercises, however, "force you to get the glutes involved, increasing that muscle-mind connection, helping you to activate those muscles in other more complex lower body moves (like squats and deadlifts), thus helping you to become more balanced in all of your exercises, and getting those lower body gains you're looking for," she explains.

A strong glute medius, in particular, translates to more stability, balance, and power in just about everything you do, explains Samuela. "Hip strengthening is so important in any sport where running is involved because improper or inadequate hip stabilization can be the root cause of many running injuries — which I've learned firsthand through many years of physical therapy for various foot, ankle, and knee issues."

While there are several other glute exercises that can add variety to your routine, mastering the clamshell exercise is an important starting point for glute-focused newbies. That's because the foundational move teaches your brain how to activate the right muscles so you get the most bang for your buck when you attempt other moves, says Samuela. (Related: Glute Isolation Exercises to Add to Your Next Butt Workout)

"The clamshell is not the only move to target your gluteus medius but it's certainly one of the most effective and one of the easiest because it's harder to rely on other body parts to execute the move," she says. "Your glutes are primed to do most of the work, which is why trainers love to use it as an activation. You get that muscle-mind connection flowing so that when you do get to those squats, for instance, you have an easier time accessing your glutes and you are less likely to totally rely on quads or lower back to do all the work."

Some other moves that can target the gluteus medius are frog pumps ("because hip abduction forces you to use more booty" compared to regular glute bridges) and hip thrusts ("which can have you relying on hamstrings if you haven't figured out how to properly activate your glutes"), says Samuela. Once you master those, you can try to step up your game with more challenging unilateral moves (e.g. single leg deadlifts or single-leg squats).

"Again, all these moves can have you relying on other muscles to do a lot of the work if you haven't figured out how to properly fire up your glutes," cautions Samuela. So it's settled: Starting off your sessions with the clamshell exercise can pay off.

How to Add the Clamshell Exercise to Your Workout Routine

While it's typically best to space out your strength training sessions to allow a given muscle group adequate time to rest and recover, daily clamshell exercises aren't a bad idea, says Samuela. "You can incorporate clamshells into your routine literally every single day, whether you're focusing on low-impact exercises to work on hip mobility and stabilization, or you're adding load and bridging and stepping up that hip-power game," she explains.

"I do like putting clamshells at the earlier part of a workout," she says. "You can start with 10 bodyweight reps or try 20 to 30 seconds worth of reps on each side." New to the clamshell exercise? Start with body weight only, recommends Samuela. "And if you add a band or weight, scale back on the reps unless, of course, you've built your way up to it."

Add the move to your regular regimen and you might just notice improvements in other areas of your routine — just make sure to thank Samuela for that stronger peach.