This is one of the most challenging fitness programs on the market.
Total Body HIIT is a total body workout that requires no gym or equipment. You exercise using your own body weight for resistance. The program is based on a fitness method called “max interval training.” In traditional interval training, you exercise at a very intense pace for a short period of time, and then rest for longer periods in between. The idea is to increase your aerobic fitness level while burning fat.
Max interval training has you work as hard as you can for 3-minute intervals, with 30-second periods of rest in between. According to the Insanity web site, exercising at this extreme intensity level will help you burn up to 1,000 calories an hour.