Bear Grylls says he's just finished a new series for the US, called "Running Wild", where he puts Hollywood A-listers to the test.

The adventurer takes six celebrities - including Zac Efron, Ben Stiller and Channing Tatum - into the wildest and most remote locations for 2 days.

Tom Arnold also gets the Grylls treatment along with Tamron Hall and Deion Sanders.

The stars are seen getting to grips with survival in the wild, away from their luxury lifestyles. 

The show will feature six episodes and each will focus on a different celebrity.

Bear says it was 'super fun'.