He has a three-year-old son who keeps him more than busy. But what makes Ian Wilson pretty remarkable is that he is 64 years old.

This week his book, 1,000 Tips and Traps for the Worried Well – A guide for men in middle life – is published. It aims to pass the knowledge he has learnt over the last 40 years on to others, in a bid to make them healthier and live longer.

"I became conscious of health and fitness in my 20s," he explains. "I was a keen surfer and realised that it wasn't just a hobby, it was a great way to keep fit. So I do it as often as I can."

But Dr Wilson is more than aware that not everyone can afford to go surfing.

"Walking is great exercise and I walk the two miles to and two miles back from my office at four miles an hour every day – that is great aerobic exercise."

He has been working on the book for around two decades.

"Originally it was going to be called Facing Forty and then Facing Fifty, Facing 60 didn't sound right so I changed the name.

"Basically I wanted to put my ideas in order for a book, first for myself and then for others. It was clear to me that lifespan could be extended and deterioration slowed down by healthy exercise and eating habits. If it would help others if my knowledge were passed on, so much the better. There were lots of health books on the market, mostly for women but some for men, but none that would be as comprehensive as mine, nor as up to date on recent breakthroughs."

Ian admits obsession with exercise is partly down to the fact that his wife is 24 years his junior, and a fitness fanatic. They also have a three-year-old son. "You definitely feel more tired than when you are in your thirties, as I was the first time round with my two adult children. In fact sometimes it is all you can do to try and keep up with them. My wife is very athletic and goes to the gym every day.

"But having a small son is very rewarding emotionally, and perhaps it keeps you that much more on your toes physically as well. But the greatest boon is that it gives new meaning to your life at a time when most other interests are beginning to flag. It really does give you a new lease of life."

Another reason stems back to his mother who died of a pulmonary embolism at 59.

"She got depressed and never recovered. Depression led to poor diet and then to osteoporosis so that when she tripped and fell over she broke a hip. The embolism followed a year later, as it often does, but she was exceptionally young for this to happen. However my family doesn't have a good track record on health. My grandfather died at 32."

After seven years studying languages and philosophy at Oxford, Ian spent a further three years training to become a counsellor, but he says he was not "PC" enough for that.

At the age of 59 he qualified as a gym instructor.

"I wanted to feel more comfortable in gyms, where often it is quite hard to feel at home. I certainly never intended to work as a gym instructor. Maybe it was that 60 was looming. It was weird being in a class of about 20 where the average age was also about 20."

He is chairman and founder of travel company WEAS, and has written books on travel. Despite his love of travel and surfing he tries to avoid air travel where possible, partly due to a blood condition which could increase his risk of DVT.

He cooks his own meals, normally stir-fried vegetables and fish or duck. He drinks very little alcohol, preferring pomegranate juice.

He admits that he has a certain fear of ageing and death which could explain his determination to stay fit.

"With death from stroke and heart attack in decline, more and more people will eventually succumb to Alzheimer's and cancer, despite advances in research into both diseases. Cancer is caused to some extent by environmental factors, so there's all the more reason to lead a healthy life. Does that I explain why I am one of the worried well?"

1,000 Tips and Traps for the Worried Well – A guide for men in middle life is published by Osculum Press £14.99. To order a copy from the Yorkshire Post bookshop, call free on 0800 0153232 or go online at www.yorkshire

postbookshop.co.uk. Postage and packing is £2.75.