You guys don't know who Arthur Jones is.....
He is the founder of Nautilus (exercise equipment) and is the person who came up with the idea of intensity over long workouts.
He had a facility in Colorado that they would train people (Casey Viator - youngest Mr. America ever, 3rd place, Mr. O) and Mike Mentzer (2nd place Mr. Olympia, only perfect score as a heavyweight at a Mr. Universe contest). These guys would do these high intensity workouts 3x/week, 20 minutes, 30 minutes tops. In 12 weeks, they would go from out of shape to contest ready.
From this point, it died down a bit, until Yates resurrected it. Then, everyone followed it again. Now Mark Dugdale is leading the group of high-intensity, low volume trainers.
So, Arthur Jones was a revolutionary mind in the sport of bodybuilding....if he didn't come along, we'd all still be training 6 days/week, 2-3 hours/day.