All types of lunges are great for working your backside, but trainer Jennifer Pattee, owner of Basic Training, is partial to a specific move: the walking lunge. "It's a great way for women to tone the butt, to get that kind of shelf butt," she explains. "Normally you can't really spot reduce and it's hard to really tone specific muscle groups, but that one works."
This exercise also tones your thighs, so consider it a must-do for shorts season. Remember to keep your weight in your heel as you come down into a lunge, and lift your toes up as you're stepping back up from a lunge in order to make the move more effective. For a full-body move, hold dumbbells.