I completely agree with all bad reviews and can add that
the language of the book is extremely poor and boring; the characters are flat with some potential to be developed, however it never happens;
some characters are totally useless and can be omitted (I wander if the author of the book is aware that good literature presupposes no excessive characters); the title is not what the book is about; the central idea is flat, one-dimensional; the plot is busy, but it doesn't really develop, it just changes chaotically; the ending is missing the main purpose of the book - the conclusion; the genre is unclear: it's too groundless for science fiction, and too plain for a fantasy. In short, it's just an example of a really-really bad piece of literature, very superficial.

I consider myself being in a good shape, not great, just good. I do not work out on a regular basis, and I am 35 years old. I couldn't finish this workout, I did only 3 miles: it was just extremely boring! You just literally walk 4 miles raising arms and doing some slight variations of walking movement from time to time. Even completely unfit people could have a bit more variety and complexity of movements.