Jennifer Aniston’s trainer says these are the three exercises that will help you perfect your squat form and build strong glutes

Woman performing side-lying leg lift in a domestic setting.

When we squat, the gluteal muscles in the butt—especially the glute maximus and medius—work together to stabilize and mobilize the hips, supporting balance and the lower body.

And if the glute medius (the small muscle on the side of the hip underneath the maximus) is weak, this can cause your knees to cave in when you squat, says Jennifer Aniston’s fitness coach Dani Coleman.