Vince and Linda Ferrigno no longer eat 30 fried shrimps every Friday night. In fact, they rarely eat anything fried. Instead of drenching their salads in dressing, they dip in a fork and spear the vegetables.

They mostly steer clear of bread and pasta, and limit their daily caloric intake to 1,500. They write down their fitness objectives, and they exercise together three days a week.

This routine was not always so. It wasn’t until Vince Ferrigno, now 78 and the retired owner of a company that made air conditioners, was in his early 70s that he started caring about his physical well-being. But even then he did not do much about it.

Working out was never his thing. “I played a little ball, but that was it. I’m not like Louie Ferrigno,” he said, referring to Lou Ferrigno, the actor and former bodybuilder who played the title character in the television show The Incredible Hulk.

After selling his company two years ago, Ferrigno decided it was time, finally, to shed the 31kg that had plagued him since he began logging 10 to 12 hours a day in the office. If he didn’t lose weight, he wouldn’t be able to enjoy his retirement. He might not even live many more years.

“I started realising I had to change my ways or 90 or 100 isn’t going to be reached,” said Ferrigno.

To help him stay on track, he and his wife, who has lost 13kg, spend a week each year at Hilton Head Health, a weight-loss resort in South Carolina, which costs $3,290 (Dh12,084) per person, per week. There they exercise three to four hours a day, eat healthy food and enjoy lectures on nutrition and general well-being.

Common wisdom has held that if you have not adopted an exercise or fitness routine in your early years, you probably won’t start in later life. But like so many misconceptions about middle and post-middle age, the idea is slowly going the way of the pterodactyl.

According to the International Health Racquet & Sportsclub Association, people aged 55 and over are the fastest-growing membership segment for the health club industry. In 1990, there were 1.9 million health club members aged 55 and above; last year, that figure hit 12 million, a 532 per cent increase.

Many clubs are actively catering to this age group, hiring trainers with specialised certifications and offering specific low-impact classes, said Meredith Poppler, a spokeswoman for the association. An April 2015 report from Marketdata Enterprises, which tracks the diet and fitness industry, estimates that 17.2 million adults ages 55 and older are dieting. The driving force is usually health.

“They had a heart attack, or a friend had a heart attack,” said Dr. John Whyte, an internist in Great Falls, Virginia, and author of the AARP New American Diet: Lose Weight, Live Longer. “They’ve been told they have pre-diabetes. They finally get a ‘jolt’ that makes them decide they need to start working out.”

Medicare will cover obesity screening and behavioural counselling, though there are some stipulations. So many people, especially those with discretionary income, are starting their programmes at fitness and health resorts, where they can exercise in a controlled environment, eat healthful food and learn about proper nutrition.

Retirees often have the time and resources to drop out of the real world for a few weeks and focus on their health.

Exercise certainly helps people look and feel younger. A recent study of participants in the Senior Olympics, a biennial competition for amateur athletes more than 50, found that older athletes’ fitness age was about 20-plus years younger than their chronological age.

What’s more, a majority of the 10,000 men and women competing in this year’s games, held in Minneapolis-St. Paul in early July, didn’t begin serious training until they were middle aged or later. Of course, not everyone plans to pole vault in later life.

For others, exercise and diet are also about mental health and changing their approach to ageing.

For the last four years, Joe Boland, 61, who sells software in Ann Arbor, Michigan, has worked with Steve Dailey, a business coach in Pahoa, Hawaii, to help him with his professional goals. Now he’s focusing on his physical health.

“I have not yet achieved my optimal weight goal. It’s been a challenge for some years,” said Boland. “One of the motivations is that I want to live to be 90, and I want to keep walking and be healthy. My orthopaedic surgeon says guys my size usually are not able to walk independently in their 70s, so I need to lose some weight.”

But weight loss is just part of the plan.

“What he will focus on goes far beyond exercise and nutrition,” said Dailey, 61, a former competitive swimmer. “Exercise and nutrition are tools for a successful life.

“They aren’t the end goal. My focus for Joe during his time here will be about developing a mindset and the tools for living an extraordinary and purposed life in his second half.”

John Striker, 71, a retired publisher who lives in New York, has hiked through Pakistan and India. He didn’t want to lose his “joy” in later life.

“It’s too easy to drift off into getting old,” he said. “The muscles are just not responding. You get up in the morning and you’re stiffer. You’ve got to draw a line in the sand and say, ‘I’m not going let that happen.’ You have to up the effort to stay in shape.”

For the last nine years, he has paid a visit to Mountain Trek in British Columbia every other year to be rejuvenated, paying $4,500 for seven nights. He hikes from five to 12 miles a day enjoying beautiful scenery, and eats no sugar or processed foods. He believes it is money well spent.

“As I get older, I need to be reminded of the potential of my body, what it’s capable of doing if I really take care of it,” he said. “My body may not be what it was at 25, but it can still respond.”