Zac Efron is busy getting in shape for his upcoming role in Baywatch, and lucky for his fans, he's letting everyone follow along on social media. The actor took to Instagram on Thursday to share a photo of himself lifting weights in the gym. "Back and bi's #baywatch," Zac captioned the snap that shows off his insane muscles. Of course, this isn't the first time we've gotten a glimpse at his killer body. After sharing a shirtless photo on Instagram in January, he then made the entire world sweat when he was photographed taking swimming lessons in LA. See his latest snap above, then try and get over your crush on him with these 25 easy steps.