Celebrity Fitness Maintains Its Hold on Hollywood

Getting in shape is more than a fad for celebs in Hollywood — it's a downright obsession! From  Neil Patrick Harris and his partner David Burtka, to Twilight babes Kellan Lutz and Ashley Greene, everyone in LaLa Land is all about getting and staying trim! Check out OK!'s gallery of these famous hardbodies.

Guys like Neil Patrick, Kellan, Matthew McConaughey and John Mayer are just as committed to their shapes as Ashley, Nicole Richie, Hilary and Hailey Duff, Kim Kardashian, Khloe Kardashian Odom and other lovely ladies!