Los Angeles : Actor Zac Efron went shirtless while filming his newest movie "Baywatch". The actor proudly showed off his bulging biceps and washboard abs, and he let his fans drool over his physique by sharing on Instagram some photographs from the set, reports aceshowbiz.com. He first posted an image of himself wearing nothing but black shorts. "Honestly I have a hard time with paparazzi but s/o to this dude," Efron captioned the photograph. The 28-year-old later shared another shirtless image of him while participating in a tire flipping competition against his co-star, Dwayne ‘The Rock’ Johnson. "'Blood, sweat and respect. The first two you give, the last one you earn.' Learned that from 'The Rock', who I happened to get in a tire flipping race with on 'Baywatch'," he captioned the photograph. The movie’s shooting is currently underway in Boca Raton, Florida. Besides Efron and Johnson, the film also stars Priyanka Chopra, Alexandra Daddario, Kelly Rohrbach and Ilfenesh Hadera. "Baywatch" is set for a May 19, 2017 release in the US.