Frequently Asked Question
The Beach Body / Insanity / P90X family of products are actually one of the worst choices for Carb Nite. They're too intense, and all of the research we have at our disposal shows us that "destroying" ourselves with exercise definitely works against us for fat loss. At best it just makes you tired.
All you need to accelerate fat loss is high-intensity interval training, which sounds similar to Insanity, but really has a very specific outlay: spend 30 seconds doing a high-intensity activity (like sprinting -- really going ALL OUT) and then follow that up with 2 minutes of low-intensity activity (like walking -- don't cheat yourself, this really should be LOW intensity, not jogging).
This exercise pattern, performed for about 20 minutes (and never longer than 30 minutes), scheduled only to occur within the first 2 days after your Carb Nite, is all you need to do for optimum fat loss results on this system.
The other days of the week, we encourage non-"cardio" activities such as resistance exercise (strength training), because your body is actually very good at staying fueled on fatty acids to power this kind of exercise. Plus, muscle is definitely a good thing!
Hope that helps!