For anyone who has done P90X or Tabata, a new craze is sweeping the nation: Insanity classes. Ok, it’s not exactly new, in fact Demi Levato is a big proponent of this American conceived class, BUT it’s new to British gyms, which is where Femail tested it out. Developed by Beachbody and made popular as DVD home workouts, it claims to burn 1000 calories in 45 minutes. It takes an awful lot of will power to actually adhere to the entire hardcore workout at home, which is probably why they're bringing out classes to British gyms. It seems a bit hardcore, but the workout is based on high intensity interval training – so right up bodyrock’s alley. Traditional HIIT workouts are all about short bursts of high intensity balanced with long cool downs. Intensity workouts turn that around, maximum intensity, short periods of rest, which makes for the extra calorie burning. But is it safe? The article seemed to be more of an advertisement than informational, so I’m not sure about the possible health risks involved. I've read several Amazon reviews about customers getting back problems from the DVD workout, or exacerbating joint problems, even an account from an experienced fit bit who tore an intercostal ligament: ALSO a lot about DVDs not working since it's from a third party seller - good thing to keep in mind if you're thinking of ordering from Amazon or Ebay. There were a few other review blogs or forum posts about their experience with the Insanity workout, so there are a lot of sources to help you decide whether the workout is a good fit for you. It seems to be quite popular and effective, so obviously not a widespread health risk. I, personally, would probably projectile vomit and pass out, but for those who want an extra intense workout then maybe these Insanity classes are for you. Then again, once I complete the 21 Day Challenge maybe I’ll have a different opinion about wanting to do a class, fit bit that I'll be. It seems like it could be a really good workout, but from reviews that I've read it seems that even total workout buffs find it challenging - good for those looking for a more intense workout/heart attack waiting to happen for beginners.