The clamshell strengthens your hip muscles and pelvic floor while (bonus!) balancing strength of inner and outer thighs, Cara told POPSUGAR. "This move is especially good for runners, as a lot of our ankle and knee alignment comes from the pelvis and hips being stable," she said.
- Lie on your side with one leg stacked on top of the other in a position similar to the fetal position. Your knees should be bent at a 45-degree angle.
- Rest your head on your lower arm.
- Brace your abs or draw your belly button in toward your spine.
- Keeping your feet touching, raise the knee of your top stacked leg as high as you can. Be sure not to shift your hips or pelvis. Your lower leg should remain in contact with the floor.
- Pause for a one count, then return your upper leg to the starting position (on top of the other leg).
- This completes one rep.