Jerry Carter runs the workout room at the Armed Forces Retirement Home.

It’s a huge and impressive facility, with all the free weights and strength and cardio machines any gym manager could want.

But at least one thing separates Carter’s workplace from a typical gym: The average age of residents at the Retirement Home is 83, Carter says.

So something called Osteo-balls, which are basically beach balls with handles and are designed to improve flexibility, are a much hotter attraction than the 50-pound dumbells.

On an average day, the gym is most crowded during the morning Osteo-ball class.

He loves the work.

“I’ve got a theory: Just keep them in motion,” Carter says. “When I see people move in here, and see their attitude and the whole mental part change from coming [to the gym], see them start doing things they thought they couldn’t do, start to want to ride bicycles here and get outside to ride bicycles, that gets me going. And I see it all the time.”

Because of the demographic of his customer base, Carter has to look after his patrons a lot closer than most guys who run gyms. He’s trained in several forms of lifesaving, he says.

Just in case.

“If they fall, we’re ready,” he says.

Nobody’s died in the gym during Carter’s five years of managing it.