it's a good work out, but really intense! I'm not sure there's a 20min work out though, they're usually 40mins-1h? Was it the fit test? I spent a very long time after doing the fitness test lying on the living room floor trying not to hurl! I did about 2 weeks of it and then started feeling really light-headed all the time, which I dunno if it was cos I wasn't eating enough, was pushing my body too hard or had some blood pressure/iron level type things going on! I did really enjoy it though, but be careful if you have any joint issues cos it's really tough on them!