This audiobook is packed with intelligent and useful information that will get you burning calories in no time. HIIT training is a fast and extremely simple way to lose weight, and is my most preferred method of training if a client's goal is quick fat loss. HIIT has not been fully introduced to the fitness world quite yet, but I think it's one of the secrets that no other athlete or bodybuilder wants to give away. I am a certified personal trainer through the National Federation of Professional Trainers, certificate number 45582.