We know what "Dancing with the Stars" pro Derek Hough has been doing during his summer vacation ... working out!
The 26-year-old showed off his pumped up pecs and biceps by going shirtless in L.A. on Wednesday.
Tens across the board.
Derek Hough -- Lean, Mean Shirtless Dancing Machine
7/15/2011 4:05 AM PDT BY Johnny Lopez
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