Pseudo-scientific nonsense - Dr Gillings is correct - independent research does not support claims made by the book.
However, I use it differently. I do 1:1 tutoring employing direct instruction, mediated learning, thinking about thinking,... which can be quite intensive. Students may get 'caught in a rut' or need to switch over to diffuse attention for even a short time 1-5 minutes- a quick chat and little movement - such as a couple brain gyms stretches, ...- and it can be like a fresh start. [ also may use them or a yoga stretch in Pomodoro breaks ] I definitely would not dedicate a part of my valuable teaching time to these activities