Go behind the scenes with free runner Levi Meeuwenberg and gymnast Mark Witmer as they battle it in the American Ninja Challenge 2.

Go behind the scenes with Rick Seedman and Brian Orosco as they duel in the American Ninja Challenge.

Kevin runs down the accomplishments and legendary status of Sasuke's biggest celebrity, Nagano.

Here's a look at one of the American Ninja competitors, a stuntwoman and free runner named Luci Romberg.

We take a look at the most universally difficult obstacles on the Ninja Warrior course, such as the log grip and the jumping spider.

No American has ever gone farther in 'Ninja Warrior' than Levi Meeuwenberg, and he's headed back for another try. Let's take a look at this worthy warrior.

A look at the five men who appear season after seaon on 'Ninja Warrior,' and who are, without question, its All-Stars.

Free-running San Francisco madman Brian Orosco nearly finished the first stage last time around and has adjusted his training to include more arm and grip strength.

Another of our American Ninja challengers, Mark Witmer, tells us a little more about himself.

Kevin Pereira and Olivia Munn talk about their upcoming run at 'Ninja Warrior' for 'Ninjafest 3,' airing November 12th.