When we initially think about it, the idea of a leg workout seems a little, well, unnecessary. After all, we've been tottering around for well over 20 years, using our legs to get from point A to point B countless times per day. Not to mention we make a point to take the stairs as often as possible.“When you walk or take the stairs, yes, you’re working your legs,” says running expert and Tone House trainer Tamara Pridgett . “But you do that all the time, so your body gets used to the routine and level of intensity. When you make a conscious effort to work out your legs, you're breaking down the muscles and forcing them to fatigue, which makes them stronger.”That’s where Pridgett’s 30-day leg challenge comes in. The three effective moves and simple running routine ahead target three major muscle groups: the glutes, the hamstrings, and the quads. Each anaerobic exercise raises your heart rate to increase your burn, so not only are you strengthening and toning your legs, you’re also working your heart and lungs. Plus, stronger legs will make you a better runner — and who doesn't want that?Lace up a pair of adidas PureBOOST X sneakers, tap into your inner athlete, and get on your marks. It’s ready, set, go time.