John Cook is Workout Wagga's newest gym instructor, having received his Certificate III in Fitness at the city's TAFE NSW campus in December last year.

A former shearer, bartender and Kooringal service station owner, the grandfather-of-three had been retired for more than five years when, in his role working with volunteers at Calvary Hospital, he became increasingly concerned about the lack of understanding around fitness for seniors.

"I kept hearing the same thing from older people: 'I don't want to join a gym because I don't want to be yelled at by someone younger than my grandkids who I can't relate to'," he said.

"But I can relate to them and they can relate to me.

"They know I can feel all their aches and pains, and I know their limitations because I have a lot myself, so there's an understanding there."

Mr Cook said he has been into fitness since he was just 10 years old, but it wasn't until the pandemic struck that he decided to pursue it as a career.

"COVID motivated me, we had a trip planned for 10 weeks over in America but had to cancel, so I thought I should do this course instead," he said.

According to a report by the National Seniors Productive Ageing Centre, 62 per cent of Australian seniors do not do enough physical activity to obtain health benefits.

Mr Cook said his classes had been well supported so far and suggested some older people needed to shift their thinking, as well as their bodies.

"Once you get going and find out you can do some of the things you thought you couldn't do, then you start to look forward to the next session," he said.

"It's all about building up your strength which builds a healthy heart so you can actually do what you want to do in retirement.

"Remember, retirement isn't the end, it's only the beginning."

TAFE NSW Wagga Fitness Teacher Helen Fisher said Mr Cook taught her and the class as much as she taught him.

"Age is no barrier as far as I'm concerned. John has been a delight and has taught many of our other students a lot about training older adults," she said.

"He's definitely brought more life experience with him into the classroom, and his experience with his own fitness issues and trouble with other trainers has been valuable."