A:  Circuit training does burn the fat, and it does get the muscles harder - even if they look a little smaller than you'd like. But to compare circuit work with isolation work... Umm... we're not sure that's accurate. They are almost completely different animals altogether. Muscles respond well to circuit training because it's such a departure from regular heavy training with fewer reps. On the other hand, muscles also need stimulation other than circuit work - more intensive work on individual muscle groups. So while it's true that some people don't do enough circuit training, and they take the heavy sets, few reps, long rests, one-body-part-a-day thing too far, you can also take circuit far too far as well.  But circuit is a really valuable tool and it's something you should definitely use in cycles. We don't recommend every other week, but maybe one week out of every month. So, do 3 heavy weeks and then do circuit weeks... Mondays: Upper body. Tuesdays: Lower body. Wednesdays off. Thursdays: Upper body. Friday: Lower body. Saturday and Sunday off.  Each time you do circuit workouts, you should try to change them up, just like you do your other heavier traditional workouts. We believe a week or circuit keeps your body guessing and growing and getting harder each month out of the year. Try even changing your diet during that week to be a little lower carb, and more meals and water intake. You'll probably find a groove that you can take into your next contest, fairly painlessly getting lean.