But what about the gluteus medius? Here's how to tone that "side" butt for a stronger run.

Squats and lunges are great for building your glutes, but they can miss your gluteus medius—or the side of the butt. Those muscles are key in the quest for a firmer derriere.

David Kirsch, founder of David Kirsch Wellness Company and author of the upcoming book, David Kirsch’s Ultimate Family Wellness: The No Excuses Program for Diet, Exercise and Lifelong Health (December 2015), has three signature moves that will tighten the side of your tush and lead you to a better butt.