Blood flow restriction (BFR) training, which Dr. Mercola perceives to be the greatest innovation in exercise training in the last century, was developed in Japan by Dr. Yoshiaki Sato in 1966. There, it's known as KAATSU, which means "additional pressure." KAATSU was brought to the U.S. just over a decade ago by Steven Munatones, after he completed a 13-year mentorship by Sato.