As long as you are going close to failure, you are recruiting all the Type 2 fibers whether you flexed or did isometrics or you didn’t. If you flexed you will come to failure a few reps earlier than if you didn’t.
And I browsed his name and came across his website. He had lot of information, but none talking about why it works. And don’t think there is anything special or unique about his 49 techniques.
I do think high reps are interesting and it maybe useful for older individuals who end up with joint pains and such with heavy weights.
