Zac Efron is taking a walk on the wild side.

The "Neighbors" star joined popular adventurer Bear Grylls on Monday's series premiere of "Running Wild with Bear Grylls," where the young actor didn't miss the opportunity to show off his well-toned chest and rippling abs.

"We reached out to him and he kindly said he was a fan of the show and that he was in 120 percent," Grylls told People magazine. "He asked for the biggest, baddest adventure and it was an honor to oblige."

In the video, Efron, 26, and Grylls, 40, stood on top of a cliff alongside a waterfall in the Catskills Mountains, and before they rappelled down the mountain, the two stripped off their shirts and put them in their backpacks in order to keep them dry.

"I can't believe how high this is," Efron said while taking in the sights.

To make sure that the young actor knows what he's getting into, Grylls threw both of their backpacks down the cliff and into the waters below.

"We started together. We're going to finish together," Grylls said, as he properly hooked both of them to the equipment.

Then, the British adventure host asked Efron again if he's ready for the challenge.

"I'm ready as I'll ever be," Efron said.

"I like to think he got to use his muscles to their max through the adventure," Grylls told People.

Aside from Efron, other celebrities such as Ben Stiller, Channing Tatum and NFL Hall of Famer Deion Sanders, will also join Grylls on his high-octane excursions.

"Running Wild with Bear Grylls" is scheduled to premiere on July 28 on NBC.