Guess Which Sexy Stud Is Workin' on His Summer Bod!

Summer's just around the corner, and lots of celebs are getting into shape to heat up the hottest season of the year -- including this mystery man with a body that's keeping him viral.

Check out the snaps ... our anon Adam is looking like The Hulk in a pair of purple basketball shorts -- bending deep into a squat to work out his strong thighs and tight backside.

He's got a whole home workout setup in his garage ... perfect for both him and his friend to pump iron in -- 'cause he's not the only member of his crew who has been working out recently.