Hollywood star Dwayne Johnson surprised gym-goers in Doncaster when he dropped in for a workout.
The ex-wrestler, known as The Rock, has been filming in Yorkshire for Fast and Furious spin-off Hobbs and Shaw.
After hitting the weights at World Fitness Gym, the actor posed for photos and with its owners.
Boss Craie Carrera said he was tipped off to the A-list arrival when someone came to assess his gym on behalf of "someone famous".
"I said as long as he puts his weights away, then it doesn't matter who it is."
Mr Carrera, who owns the gym with wife Alicia, praised the down-to-earth actor.
"He was very talkative, a nice guy, really genuine, just like an everyday person," he said.
"He towers over you. He's about 6ft 6in.
"He's got fairly big arms - as a bodybuilder you're eyeing up this sort of stuff all the time."
Mr Carrera, a bodybuilder, said the ex-wrestler had sent a staff member to inspect the gym before arriving.
"A guy came in and asked if he could take a few pictures because someone famous was coming into the area," he said.
"He just wanted some pictures of the gym so his client could see if it was up to par and wanted to see what the weight stacks were like and the dumbbells, if they were heavy enough.
"We thought it was a bit strange but left him to it."
The star has been filming alongside Idris Elba at Eggborough power station, near Selby, for the Fast and Furious franchise spin-off.
Other actors appearing in the action adventure include British actors Jason Statham and Vanessa Kirby.