Olympic swimming gold medalist Nathan Adrian; pro-surfer/model Alana Blanchard; pro soccer player Landon Donovan; motocross champ Carey Hart; Olympic track and field star Marion Jones; and Wieber.

Cam Newton and Nathan Adrian, the two largest competitors ... "I'm a competitor, so whatever it requires me to win, I'll do." Adrian, a former Olympic swimmer, admitted he wasn't as comfortable ...

Christy Carlson Romano is out on 'Special Forces,' but she made it further than 10 other celebs. No one is more surprised ...