Do It: Lie facedown on the floor with your arms folded under your head, legs extended straight behind you. Bend your right leg, knee pointed out, and place your foot on the back of your left knee, keeping both hips on the floor. Contract your right butt cheek and lift your right knee a few inches off the floor without raising your hip. Pause, then return to the starting position. Complete all reps on the right side, then repeat on the left side.
Don’t let the look of this one fool you: It is one of the most challenging and effective moves for targeting your external hip muscles, which have a major impact on your glutes.