I did both - but I think it depends on how well you are in shape and your personal goals. If you are in good shape, you can do month 1 + other exercise (same day). I did this bc I liked to run - but also I added in weights (which is my main complaint -I would have lost muscle tone if I didn't). I also substituted some days for my workouts which were as intense or more inenses. But - I wasn't obsessed with losing weight - so I could go off program. Month 2 - which I'm in the midst - the intensity level is more at my level - so I don't do a double workout - but I do substitute workouts on some days.

Try it and see how you feel. You'll know if you need to cut back on your running as you go along.

I just got Insanity. For those who have done it, did you give up your other workouts for 2 months and do the DVDs exclusively, or did you intersperse it with other stuff? I also really enjoy running but I'm worried the Insanity workouts are going to make me too sore to keep training. Any advice?