Spot Toning and Muscle-Building Tips

10 Muscles That Are Hard to Sculpt

From stubborn muscles that just won’t pop to secret spots you didn’t know you should (or could) hit, we reveal how to train your body's trouble zones

Have Healthier Hips

If you've heard of your piriformis, it's probably because you've read how to massage it with a foam roller. But just because it's tight enough to be massaged doesn't mean it's getting a workout, says Jessica Cassity, fitness editor at Prevention magazine.

The piriformis is used for rotating your leg so that your knee goes from pointing forward to pointing to the side, Cassity says. As such, most workouts miss it: "Because it's not something you work in a linear path—in squats, lunges, and other exercises, your knees are facing forward throughout," she says. "If you were doing ballet, then you'd be working it a lot more."

Challenging this muscle is important, though: If you suddenly have to turn—in a sport like soccer or to avoid a speeding cab in the street—a strong piriformis will allow you to make split-second changes in direction. And you can work it with a simple, Pilates-inspired exercise called a clamshell, Cassity says. To do it, lie on your side on the floor, with your hips and knees bent 45 degrees, almost like a fetal position. Keeping your feet touching, raise your top knee as high as you can without moving your pelvis (as the name suggests, your legs should resemble a clamshell that's opening). Pause, and return to start. Repeat, then flip over and try it on the other side.

A quick warning: When you're working your piriformis, Cassity says, you run the risk of sciatica symptoms and pain. To avoid this, perform the figure-4 stretch: Lie on your back with both legs extended straight out, feet and knees pointing up. Bend one knee to place that foot just above the knee of your other leg, so that your legs form a figure-four. Bend your still outstretched knee, and grasp your shin just below the knee—one hand should go through the hole between your legs, the other outside your outstretched leg. Slowly pull your knee toward your chest and feel the stretch. Repeat on the other side.