Exercise New Zealand chief executive Richard Beddie said the public perception of gym-based exercise had shifted significantly in the past few decades.
"What's really different now is that exercise is mainstream. Twenty-five years ago it wasn't," Mr Beddie said.
"The joke was that the only people that had personal trainers were movie stars or elite athletes. Now it's not unusual and it's a mindset change not only individually but broadly in society."
Equipment-based exercise - lifting weights, running or cycling in a gym or at home - has become the fifth-most popular sport or recreation activity in the Whanganui-Manawatu region, with 8400 annual participants. This sits behind walking, swimming, cycling and fishing.
Sport New Zealand general manager of community sport Geoff Barry said there was an increasing number of people who were time-poor and unwilling to make season-long sporting commitments.
He said conversely, there had been an increase in demand for casual, time-flexible activities, such as running, walking or the gym.
Sport New Zealand's Active survey found 5.1 per cent of respondents in the area were a member of a gym or fitness centre in 2007/08. By 2013/14, the rate increased to 13 per cent, although this was still below the national average of 19 per cent.
Mr Beddie said one of the major demographic changes in gyms has been the increase in patronage by older people looking to maintain health and mobility.
"Now it's very normal for groups of people in their later years to exercise.
"There's a cliche in our industry that people join for beauty and they stay for health.
"If you're 20, you're more interested in how you look. But when you're 60 you're more interested in how you feel," he said.
"By going to that class activity every Thursday, it might mean you can still pick up your grandkids, or you can still walk to the bus stop. [Older attendees] have completely different drivers and motivations [than younger members]."
Mr Beddie said the vast majority of people found it difficult to make time for regular exercise but physical health was possibly the most important asset a person had.
"It's all about priorities. You're investing time now to invest in the future."
Staying fit for the next generation
A local gym has noticed a surge in older members future-proofing their health and well-being through regular exercise.
Mere Whanarere, facility manager at Inspire Health and Fitness Centre on Wilson St, said a sizeable chunk of the gym's members joined after decades of infrequent exercise.
"We do cater for a large amount of what I would call aged members, those over 60. Out of our 800 members, the average is about 44," she said.
"I think the aged population has grandchildren, which gives them more purpose to be well for longer. Most of them [say]... 'I want to be here for my next lot and my great grandchildren'. That's definitely a driver."
Ms Whanarere said the social aspect of the gym was just as important as the physical for many members .
"We definitely promote engaging, member to member. It's not just a gym, it's a social place.
"I tell our staff our key theme is customer service and making everyone feel a part of the family.
"We have all walks of life, but we encourage everybody to know each other."
