The Best Butt Exercise You’ve Never Tried

Photo courtesy of Functional Movement Systems

To firm your butt and hips, you don’t need a gym membership or archaic seen-on-TV contraption — all you need is a water bottle.

The move you see above is known as the Cook hip lift, named after its creator, physical therapist Gray Cook. It’s a cousin of the basic hip raise — a butt-toning exercise in which you lie on your back, place both feet on the floor, and lift your hips. (If you’re imagining something dirty, you’ve got it right.) But Cook’s variation not only works your core, glutes (butt muscles), and the back of your legs, it’s also kinder to your lower back.

Start on your back with your knees bent about 90 degrees, your feet planted on the floor in line with your shoulders. Grab your right thigh and pull your right knee toward your chest, pinning a water bottle, a tennis ball, or a rolled-up towel in the crease of your hip. Lift your left toes off the floor. Keeping the bottle in place, raise your hips as high as you can, pause, and lower your rear back down.

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“Too often during a normal bridge with both feet on the ground, people have a tendency to move more from the lower back and round the low back too much at the top of the exercise,” said sports medicine expert Lee Burton. By using your lower back to lift your hips, you neglect the body parts the exercise is meant to target: your glutes (butt muscles) and hamstrings (back-of-thigh muscles).

The fix: Pulling your thigh to your chest prevents your low back from arching. This trick also keeps the lower back locked into the same position during the exercise, which prevents it from flexing to help you raise your hips up. With those muscles out of the picture, you force your glutes and hamstrings to initiate the movement.

“Clenching an object between your thigh and belly ensures that you keep your thigh in the right place,” Burton told Yahoo Health. “If the object drops, you’re not holding the thigh in and you’re getting too much motion in your low back.”

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Raising the toes of the other foot makes you press your heel into the ground as you lift your hips. This sends a neurological signal to your glutes and hamstrings that activates these muscle fibers during the exercise, Burton said.

To make the Cook hip lift harder, don’t hold your leg with your hands. “Now you’re forcing yourself to actively keep that knee and thigh at your belly since your hands aren’t helping you,” Burton said. In addition, move your supporting leg in toward the midline of the body so your core has to work harder to keep your body stable.

Perform the exercise as part of a warm-up, in between sets of heavier weightlifting exercises such as squats, or as a standalone strength exercise. For a full breakdown of how to do the Cook hip lift correctly, watch athletic trainer Mike Boyle demonstrate in the video below.