The Melbourne man said Canberra was an event he enjoyed as it gave him a chance to spend a bit of quality time with his daughter Nicole who is studying medicine at the ANU.

"I ran the marathon in Canberra last year," he said. "I managed to break four hours, it was great. I have been here a couple of times but I love coming back to visit her and of course it allows me to tick off another number."

The 53-year-old said he had completed close to 80 marathon and ultra marathon events when he dreamed up going for the century.

"That is my goal now," he said. "Last year I did six so if I can do that again this year that would be great. Barring any injury or mishaps, hopefully by 2020 I can reach it."

So far this year he has completed a marathon at Wangaratta, he has Canberra booked to run but that was as far as he had planned.

In the three or more decades he has run marathons he has seen his time change but said something close to four hours he would count as a successful run.

His first marathon was in 1986 but the seasoned runner said year after year he was reminded it was not an event you could be complacent about.

"I enjoy the challenge," he said. "My view is anyone can do a marathon but you can't be arrogant about running it. It is not something you decide on a Friday and do on a Saturday. You have to do your training and be prepared."

Mr Kahlberg said he had a few tricks and just one tradition when he ran. In nearly every event he wears a Comrades marathon cap he got after completing 10 marathon events in South Africa.

He said he was trying to squeeze in an international marathon run as he ticks off the final few.

"I ran the Berlin marathon last year and have completed the New York marathon in the past," he said. "I'd love to be able to do London or one of the big six. It is becoming quite difficult to get in on the ballot into those races."