Is this the show you are referring to:
YouTube - Makoto Nagano Sasuke / Ninja Warrior 14
Looks like a more hardcore version of the current ABC gameshow Wipeout,
YouTube - Wipeout! Episode 1 Part 1 which in itself was influenced by all the Japanese extreme gameshows in the 80s and 90s like "Ultra Quiz" 風雲！たけし城/"Fuun! Takeshi Jyo" (AKA Takeshi's Castle) and ウッチャンナンチャンの炎のチャレンジャ/Unchan Nanchan No Hono No Challenge (AKA Challengers of Fire). They do seem like fun but as with the reality shows like CBS' "Amazing Race" they do seem pretty grueling and intense.
YouTube - TRANS AMERICA ULTRA QUIZ
YouTube - 風雲たけし城 1/3