Insanity
If you're starting a workout program that calls itself "Insanity," you know it's going to be over the top. This is one of the most challenging fitness programs on the market. Insanity is a total body workout that requires no gym or equipment. You exercise right at home, 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 youraerobic fitness level while burning fat.