I do remember Yogi Coudoux, but I don't think it was an hour!
just tried searching the guy. still doing crazy shit. here's what someone said about the underwater thing, not sure how accurate.
I only chose this person because it was a tombraiderish type of thing. As for breath-holding and mental discipline.....back in the early 80's on a program called 'Thats Incredible' a yoga master called Yogi Kudu or something like that.....folded himself into an acrylic box that measured about 4 square feet. The box was then sealed airtight and placed on the bottom of a filled swimming pool for an hour. After which time the box was lifted out opened and he emerged just as slowly as he went in but was completely unharmed having been folded up and with no space to move and little air for breathing. It was calculated that he had filled the box with about 2/3rds of his own mass and had about 1.33 cubic ft of air to breathe for 1hr.