heartthrob doesn't just swim, box and play football to look good. "When I don't have the chance to go to the gym, my whole attitude's kind of down," Lutz (in Venice Beach, Calif.) told PEOPLE. "When I can go to the gym or hike, it just builds up my energy and my confidence."
SHEMAR MOORE 41
The Criminal Minds
star (in Miami) has a hard body and a soft spot for Mom: For the past five years, he has completed a 100-mile bike ride to raise money for MS, a disease his mom lives with.
Jake Pavelka 31
"The trick to having abs is to train with weights and then do high-rep crunches to tone them," says the former Bachelor
(in Hawaii), who also likes to spray tan. "You smell like a candy bar, but you look okay."
"I'm physically stronger and better than I have been for a few years," said the soccer superstar (in Malibu).
Gavin Rossdale 45
The rocker (in Antibes, France) has trained in kung fu, but tennis is his true passion: "It's incredibly physical."
"He's always been in shape. He loves being outdoors and hiking," says a pal of the actor (in Manhattan Beach, Calif.).
Marlon Wayans 39
To stay trim "I try to do an hour of cardio five times a week and a 30 minute circuit," says the comedian (in Maui).
Diego Boneta 20
The rising star of the film Rock of Ages
doffs his shirt (in Miami).
CHRIS HEMSWORTH 28
The avid surfer (in Newport Beach, Calif.) bulked up to play Thor with "good old-fashioned weight lifting," he says. Plus "every hour or two, something was being consumed. I had chicken more than anything else. The idea of never eating it again is appealing."
Since becoming a dad, the actor (in Trancoso, Bahia) had to change up his workout routine: He now combines push-ups and squats with doing pull-ups on his kids' swing set.
Josh Hopkins 40
"I'm naturally more muscular than skinny," said the Cougar Town
star (in St. Barts), who is known to squeeze in 45-minute cardio workouts during his lunch break on-set.