The Leg Workout That Will Turn Your Lower Body to Jelly—in 15 Minutes!

Hit your legs from all angles with this quick, grueling circuit Working your lower body is tough. The movements that train your quads, glutes, and hamstrings—like squats and lunges—require a ton of effort and a lot of willpower. No wonder leg day gets a bum rap. But you don't have to spend 45 minutes …