Since the body uses fats and carbohydrates for energy, you should not neglect the legs! The reason is that the quads and glutes are your biggest muscle group and therefore need more energy to perform work. For inatance, do some bicep curls and then do some squats. I guarantee you start sweating quicker doing squats than you will bicep curls, because the legs are the biggest muscle and need more energy of fats and carbs for fuel to perform work. Click on the link below the picture for an awesome quad and glutes routine from Muscle and Fitness Magazine.