HIIT Training is an intense workout technique whose origins remain under constant debate but, was popularised by fitness expert, Arthur Jones. Although not a new training technique, it has surged in popularity over recent years drawing the attention of amateurs and professionals alike. It is for this reason that I have decided to write a book breaking down high intensity interval training. The book consists of two main sections that are broken down into sub-sections, from the history of HIIT to mistakes to avoid when undertaking the gruelling training method.