Fit and Strong at 75: This OKC fitness instructor’s advice is to ‘just keep moving’.

OKLAHOMA CITY, OKLAHOMA -- They shuffle in at the end of a busy work day, a little stiff from sitting, a little groggy from lunch, but ready for Judy Brown to do what she does best.

"Oh my gosh," she exclaims. "These are all my kids."

3 times a week, one hour, warm up, legs, back, chest, triceps, biceps, shoulders, abs, the whole body and a little encouragement from a grandma who's probably stronger than you.

Brown admits, "My class is what keeps me going. They have supported me and kept me moving, and I feel young, and I feel good when I come here."

She was a mother of 3 going back more than 30 years.

Judy bought a Jane Fonda VHS tape, then a book.

She started going to classes then got certified so she could be the leader.

"I never missed a class," she says. "Then I thought, 'well if I'm a teacher then I don't have to follow anybody', so that's how I got started teaching."

Her class is still pretty full even as New Year's resolutions begin to flag outside her class at The Weight Room gym in Oklahoma City.

At the strong age of 75, Judy keeps her 'kids' coming in.

"She's my fit grandma," says Mark Clifford. "She's an inspiration for sure."

"I home someday I can lift as much as she can," says another longtime student Lisa Thompson.

"I am very fortunate to still be teaching," says Judy, "because I keep moving."

This workout session has a couple of unexpected breaks.

Judy gets some encouragement from her husband.

Her two sons walk in to give mom a squeeze too.

Judy herself finds motivation in family, students, and momentum itself.

Once she started it never made sense to stop.

She keeps promising one year at a time.

Her 'kids', as she calls them, keep promising to show up, and so the heavy lifting continues.

'Downtown' Judy Brown, as her students call her, just keeps getting stronger.