This exercise targets the muscles of your glutes and hamstrings to create leaner, stronger legs, and a tighter, lifted rear. Stepups also work your quadriceps since they require you to straighten your knee against resistance.
How to do it: Stand in front of a bench or step and place your left foot firmly on the step. Press your left foot into the step and push your body up until your left leg is straight. Lower your body back down until your right foot touches the floor and repeat.
Keep your chest up and core engaged the entire time. Keep your weight balanced evenly, not leaning too far forward or too far back.