Forget squats — I use this simple Pilates exercise to isolate your glutes and reduce lower back pain

While squats and lunges are a fantastic way to strengthen the glutes and lower body, there’s one simple Pilates exercise that really isolates the gluteus medius — a smaller muscle on the outer hip that often gets lazy as the larger gluteus maximus or hip flexors tend to take over during lower-body moves.

I’ve been practicing Pilates for the past 15 years, and it’s a staple exercise in my lower body workouts — read on to find out how to do the Pilates clamshell with perfect form, plus the progressions to try once you’ve mastered the bodyweight move.

As a reminder, what works for me might not be right for you and your body. If you’re a complete beginner, pregnant or postpartum, or you’re returning to exercise following an extended break or injury, it’s always best to seek advice from a qualified professional.

What is the exercise?

As with all Pilates exercises, the key to the clamshell exercise, or clam, is moving with good form. The focus during the exercise isn’t just opening the knee, but engaging the core and keeping the torso and hips perfectly still.

To engage your core, think about squeezing your belly button into your spine, bracing your midsection. I also like to think about squeezing into a pair of jeans that are a size too small, zipping my abs up and in — this helps with engaging your pelvic floor muscles as well as your abdominals.

You won’t need any additional equipment for this exercise, but lying on a yoga mat can make things more comfortable.

• Lie on your side on an exercise mat, with your knees bent at 90 degrees and your heels in line with your sitting bones.
• Engage your core muscles and ensure your spine is straight.
• Keep your feet pressed together and exhale as you lift your top knee toward the ceiling. Don’t let your hips rock backward.
• Inhale as you lower the knee with resistance. Imagine you are closing a heavy book, not letting your leg flop back down
• Complete 8-15 reps on one side, then change sides.

What are the benefits?

Isolates the glute medius

As mentioned above, the clamshell is an excellent exercise for targeting the small glute medius, which sits on the outer hip. It’s often the laziest of the glute muscles, as your glute maximus and hip flexor muscles tend to take over to drive powerful movements. You’ve probably seen ways to work this muscle for a more toned "side booty," but its key job is to stop your knee from caving inward during moves like squats, and when running and walking.

Improves pelvic stability and hip mobility

If, like me, you’re a runner, your glute medius has another important function — it stops your pelvis from dropping as you lift one foot off the ground, then the other. By doing clamshells and keeping your hips stacked, you’re training your pelvis to remain stable as you move your lower body. You’re also working on external rotation of your femur in the hip socket and strengthening the muscles that control hip rotation.

Reduces lower back and knee pain

As mentioned before, the job of the glute medius is to keep your knees in line as you walk and run. This, in turn, takes the pressure off your lower back. This is one of the best exercises you can do to protect your joints from weak hips.

What are the progressions?

Once you’ve mastered the bodyweight variation, and you can easily complete all of your reps with your hips perfectly stacked and your waist lifted off the mat, you can add intensity by trying one of these progressions:

• Add a resistance band: Adding a mini-band increases the tension the glute medius has to fight against. Loop the band just above your knees and push against it as you open the knee.
• Elevate the clam: Lift both feet into the air so they hover about ten inches off the mat, keeping your bottom knee on the floor. This increases your range of motion and helps target the deep rotators of the hip.
• Add a plank: This variation really works your glutes and oblique muscles. Keeping your knees on the floor, raise onto your forearm in a side plank. Squeeze your core and perform the clamshell while holding the modified plank. Your bottom glute will be working even harder here to keep your hips lifted.
• Add a kick: Finally, increase the load on the hip by opening the clam, then extending your leg, tapping your toes together, then closing the clam.

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