Zac Efron: Pumped Up on 'Paperboy' Set!

Zac Efron shows off his muscles in a white tank top while on the set of his new film The Paperboy on Wednesday (August 10) in New Orleans, Louisiana.

The 23-year-old actor plays the brother to Matthew McConaughey‘s character in the upcoming flick, based on the 1995 Pete Dexter novel.

The thriller will follow a Miami Times reporter as he returns to his Florida hometown to investigate the imprisonment of a death row inmate.

Zac picked up the award for Choice Red Carpet Fashion Icon: Male at last weekend’s 2011 Teen Choice Awards.