I practice high intensity training split for two years (after years of jogging who brought me that -genoux problems ... fasciitis and efficiency to almost zero fat loss). So far my main sources of information were books or articles written in English. So this book, what a nice surprise! And with scientific references that! It's a little technique (a lexicon would be welcome) for a person unaccustomed to the genre, but so exciting! Especially in a context where the multi-billionaire fitness market seems Origin Lock any information on the subject with always the same message: jogging / fitness group sessions (moderate effort) is good for health, increasing lung capacity / heart, loss of excess weight (buy a magazine like "runner world" for example, you will read a condensed incredible bullshit with vague references to studies just mentioned-a Swedish study demonstrated. Bla Bla blah) ... You really want to get stronger and lose your excess weight: made of HIIT, become primal; o) I take a star for the austere layout and font scriptural end of the book, and particularly ugly illegible. But it does not prevent you to buy it eh!