Define "Works for everyone"?
Mentzer defines 'everyone' literally, as every human being. Obviously, we all have different genetics, so some will develop bigger muscles, and more quickly than others. Also, we all have different recovery abilities, from hard, intense workouts, or any physical activity. I don't necessarily agree with him, but his theories and principles make sense, otherwise, how could we have medical science, that applies that all humans, if we all responded differently to medicine and surgical operations? Mentzer maintains that his HIT workout system works more quickly and efficiently that others, that is, with much less time in the gym/week.