One day Ken went for a run: 40 Melbourne Marathons later...

"Every year I keep saying it's the last one... all up I reckon I've run about 50 marathons including London, New York and the 2000 Sydney Marathon that followed the Olympic course," he said.

His first Melbourne Marathon was in 1980. He first heard about the event while on a climbing trip in the Himalayas.

"When I returned, I asked my 16-year-old son John if he was interested in training for it. We agreed we both would... I didn't know back then it would be the start of a lifetime of marathon running," Ken said.

He said staying fit is important, which also enables him to follow other passions like golf, skiing and bushwalking. He is also still gainfully employed, which maintains an active mind.

"I enjoy seeing all the young people on my train to work each day," he said.

Staying fit doesn't come about through any training regime - he admits to having none whatsoever.

"I go for runs when I can fit them in. Occasionally I'll do a long run over the sand dunes at Sorrento or along the Yarra in Ivanhoe. I jog very slowly now. At 86 your mind is willing but your body just doesn't move the way it used to," he said.

With a tailwind, he thinks he might complete the course in six hours. It also depends on whether his eight kids run with him to provide extra motivation.

While he has fond memories of his 39 Melbourne Marathons, 1990 is one that stands out.

"My son Matthew had a big 21st birthday party on the eve of the event. I stayed up late and enjoyed one too many beers.

"My wife hid my runners so I couldn't wake up at 5am to go in the marathon. What she didn't know is that I had a second pair of runners in the closet.

"Gee that was a tough day," he said with a big grin.

The Melbourne Marathon is on October 13.