I'm starting the hit workouts that are provided from Scott and was curious on if I should be doing cardio or not. I'd like to get that lean/conditioned look. Problem is I sit at a desk 10 to 12 hours everyday so I don't burn many calories until I go workout. The workouts are twenty minutes of hit and I'm wondering if I should add maybe 20 minutes of cardio after that or not. With my nutrition the wife and are in the process os going vegan. Any advice is welcomed. Thanks. 

HIIT is very taxing on the central nervous system (CNS). It also burns a lot of calories in a short time - typically 15-20 minutes. I would not add steady state cardio at this time. If you are hitting the gym and doing HIIT, this should be enough to get you lean. Usually for contest prep and to get to sub 8-9% bodyfat, adding in extra days of low intensity cardio coupled with HIIT and weight training is adviseable.

I would not do HIIT more than 3 times a week. If you start feeling drained or your workouts aren't as productive, it means your CNS has not sufficiently recovered which means you need to cut back on the HIIT or take an extra day or two to rest. If you don't listen to your body and try to do too much, you will not only stop all fat loss but also any new muscle growth. The great thing about HIIT is that with training and a proper diet less is better than more.

John

15 - 20 minutes of HIIT cardio 3 times a week can make a MASSIVE difference along with lowering carbs on rest days. Are you short on time? Why are your circuits only 20 minutes? I also suggest doing the 20 minute circuit, resting 3 - 5 minutes and then doing it again.