It's Japanese and is a physical challenge show, based on obstacle courses.
(It's on every night at 6:30 p.m. and 10:30 p.m. here in New York.)
Each competition starts out with 100 competitors. There's 4 level of challenges that are timed. Only those who complete level 1 in the allowable time move on to level 2 (and so forth). I believe, there are at least 2 competitions each year.
I think that in the entire history of the show (maybe 10 years?), there has only been one person to complete all 4 levels in the allowable time(s).
They've had U.S. Olympic Gymnasts like the Hamm brothers on there.
The thing that surprises me are the regular guys that do so well. There's a Japanese Fisherman and a Japanese Fireman and a Japanese Garbageman who each competiton, regularly make it to level 3 - these guys aren't pro athletes just regular working guys who are amazingly strong and athletic.