There are four main muscles you want to target when doing leg exercises. These are the quadriceps, the hamstrings, the calves and the glutes. For each of these muscles there are targeted exercises that you can perform during a lower body workout to maximize results. First off, for the calves the most famous machines are the calf-press machines. There are two main versions of these machines: one where you stand up and one where you sit down. In either case the objective is to lift weights isolating your calf muscles. For maximizing effort with the quadriceps look for leg press machines. Exercise your hamstrings with leg extension curls. Finally, for your glutes you can grab a pair of dumbbell and perform lunges.