Freerunner (2011)

Free runner Ryan competes in races put on by a local promoter  who has cameras all over the city and generates income through a site which handles online betting on the outcome of the races.  Ryan is a good guy and hopes to save enough money to take care of his grandfather and girlfriend.

When the racers are knocked out and kidnapped, they wake to find themselves in a white room with exploding collars around their necks.  The mysterious Mr. Frank has decided that his billionaire friends would be amused by a competition where the winner gets a million dollars, and the losers heads explode.  And he's right because the rich bastards are totally into it.  Since we don't really know any of the other characters, I guess we'll root for Ryan.

This reminded me of several other movies, especially Running Man.  The exploding collars reminded me of Battle Royale, as well as 1991 film Deadlock, with Rutger Hauer.  Both those movies were better than Freerunner - although don't hold me to that on Deadlock since I haven't seen it since the 1990s. It may not have held up well, but Rutger Hauer is usually at interesting at least.

Be prepared for some shakey cam action during the races which is annoying since you can't see the stunts that well.