Zac Efron Shows Off His Post-Bulk-Up Abs in Manhattan Beach

Zac Efron has bulked up while preparing to portray a marine in a new movie "The Lucky One" last year. And now the former "High School Musical" actor shows off his post-training six-pack body while out and about in Manhattan Beach, Calif.

Wearing only short denims and a pair of white sneakers, the "Charlie St. Cloud" hunk was seen enjoying a warm summer day and rolling around the beach on a skateboard in one picture. In another image, he was snapped barefoot and playfully hanging on a pole swing.

Zac bulked up with the help of trainer Logan Hood, and kept his diet in check by following healthy eating tips from nutritionist David Allan. "Zac put on 18 lbs. for his role in The Lucky One," a source said. "Since then, he's lost weight but he's keeping up a fitness routine."

Revealing about what kind of activities Zac likes to do to maintain his toned bod, the source added, "He loves being outdoors, hiking and exercising outside. He's always been in shape."