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Michael Phelps

After all that time in the pool, it's no wonder Olympic swimmer Michael Phelps is so buff! The 14-time gold medalist's rigorous training regime keeps him lean, despite a diet of a whopping 10,000 calories a day. He's set to show off his bod again next month when he competes in the games for a final time at the 2012 Summer Olympics in London.

The Boys of Summer

Hugh Jackman, Joe Manganiello, Chris Hemsworth, and other hot stars show off their buff bods.