OMG, I have just done Jillian Michaels (of the ofthe trainers from the biggest loser) DVD, burn fat and boost metabolism and ITS SO HARD!!! I generally go to the gym 2-3 times per week so woul consider myself reasonably fit and i puffed and panted the whole way thru. If you want an intense 60 min work at at home - i defo suggest you try this!!