OK, this book has some things going for it that help set it apart from other exercise books out there. There are some decent footnotes and the main points all have some scientific backing behind them. It also gets bonus points for pointing out that super levels of fitness, low body fat, and big muscles do not actually equal high levels of health, longevity, and well-being. There is also truth to the author's assertion that there is a quality of life issue involved in the time spent working out when you could be doing other things.
There are a lot of other good points, too, but they are all pretty general and common sense. For example, "The Big Five" (or "Big Three") has been exercise 101 for over a century because of one simple reason: there are really only 5 natural movements that the human body can reasonably perform with weights: Overhead pressing, pulling/pushing down with the lats, pushing out from the chest, pulling into the chest, and standing up to extend the legs. It's also been long understood that the three pillars of weight training are training, diet, and rest: if you're struggling to make gains, you should look at all three instead of just training harder, which can be potentially counterproductive. Again, this should be common sense, but it must be said nonetheless.
However, for a book that's supposed to be so predicated on "science," the science that's presented is often poorly understood or perhaps even deliberately confused to support the author's own selling points and shortcomings of their training system.
Example #1: There is no scientific evidence supporting "Max Contraction," just John Little's marketing. None. The authors' emphasis on doing reps very slowly and counting the time spent under stress are also scientifically dubious with mixed support in the literature.
Example #2: There is no scientific evidence that says old Nautilus machines are conclusively better for fitness than free weights or other manufacturors, but the authors own a gym that specializes in this equipment so it's cited as being the ultimate in training. There is some truth to machine-based workouts being easier on certain joints, and they get bonus points in HIT because they allow you to safely go to failure without a spotter, but the authors barely reference those key points.
Example #3: The studies that are cited are often sort of thrown together. Some will involve elderly or extremely out of shape clients who would have benefited greatly from the introduction of just about any physical activity. The authors point this out when the studies in question apply to aerobic exercise as a reason not to trust those studies, but fail to keep this in mind when studies on similar parameters agree with their own conclusion.
Example #4: If you look up pictures of John Little and most of his clients, you'll mostly find a group of fairly average looking men with very few impressive physical specimens. You'd be hard pressed to tell if some of them work out at all, and I think most people at least want noticable gains from their gym experience. Little asserts time and again that success in sports and bodybuilding is mostly because of genetics and that less than 2.5% of men have the "genetic potential" to build large muscles. However, if you go to just about any gym with a reasonably large clientelle, you'll see several amateur bodybuilders who show that the genetics necessary for this kind of size are not so rare, if in fact they have any "special" genetics at all. Little's "12 minutes a week of max contraction" disciples tend to look absolutely puny by comparison.
That's what I found most disturbing about this book: the misrepresentation of science in the book's emphasis on "genetic potential," particularly the role of genetically determined levels of myostatin as the holy grail, when it comes to building muscle. While myostatin inhibition does help produce large muscles with little bodyfat, the science simply does not say what the authors assert it does. That section is badly written, poorly researched, and misleading.
For examples, the book says that professional bodybuilders refused to be tested for myostatin levels because it may harm their endorsement deals, when in fact many (such as the FREAKISH Ron Coleman, who bags millions in endorsements) were tested for a variety of genetic differences and the results usually came back that they were, in fact, fairly average. Only a couple of examples of genetic irregularities were found and those came from lesser known bodybuilders--most famously, "Flex Wheeler," who has extra muscle fibers. The science just didn't find that bodybuilders are necessarily genetic freaks when looking for the things that it expected to find.
But the myostatin discussion gets worse when discussing myostatin inhibition in racing whippets (and the rare, super muscled freaks known as "bully whippets"), the authors say that "Bully whippets" win most of the races. This is the exact OPPOSITE of reality: Bully whippets are typically euthanized by breeders as puppies because they perform very poorly in races. Their added bulk slows them down and they tend to be injury prone.
That gets to another point the authors overlook: high levels of myostatin inhibition is not associated with greater athletic performance. In fact, myostatin-inhibited mice have been determined, pound for pound, to have weaker muscles than typical mice and much more prone to tendon and joint injuries. Belgian cattle have major problems dealing with stress, are more injury prone, and are also weaker, pound for pound, than typical cattle. It remains to be seen how the handful of positively identified humans with the special genetics that the authors say will make them champion bodybuilders will turn out.
The authors also hint that myostatin inhibiting drugs, their perceived holy grail for supplimentation, were stopped by pharmaceutical companies "for no reason," perhaps even because it may cost them sales of other suppliments, but the truth is that all the drugs that were tested were having potentially lethal effects, such as causing enlargement of the heart. Even then, a couple of myostatin inhibitors were sold as bodybuilding suppliments for a while in the 2000s, but they never caught on because they proved worthless. I don't know if any of them are on the market today.
All of this casts doubts on this book's "scientific" marketing angle. If you follow the authors' advice you may become fitter and happier, as their suggestions will help you achieve and maintain a modest level of fitness, but take the authors' discussion of genetics and unusual training techniques (like "Max Contraction") with a healthy grain of salt.
If you want to get in and maintain a "normal" baseline level of practical fitness with an average body type, you could do a lot worse than to do what this book says. However, if you wish to be a bodybuilder or athlete, you should look elsewhere my friends.