Since taking part in his first City2Surf event in 2009, Reid has run, and run, and run, all in the name of raising awareness of, and funds to fight, Multiple Sclerosis.

And this weekend the 65-year-old will tackle his most ambitious challenge yet as he hits the road in an attempt to run from the coastal city of Eden to his hometown of Bombala.

It's a roughly 90km route that will include tackling Big Jack Mountain which Reid will hit roughly halfway into his run.

"I've been psyching myself up every night thinking about it," Reid said of tackling Big Jack Mountain road.

"The City2Surf might have heartbreak hill but down there the challenge is Big Jack Mountain which is about six or seven kilometres straight up.

"I'm not sure what will be going through my head but hopefully but the time I hit it I'll be well into the run and into a good rhythm. It's all a mental challenge."

Over the past five years, Reid has raised thousands of dollars for the Multiple Sclerosis Society through his running; a pursuit he first took up to deal with the stresses of life after his wife Annette was diagnosed with the disease.

MS is a degenerative disease that attacks the nervous system with no known cure. It can lead to complete paralysis of the sufferer.

Reid's epic run will take him from Eden to Cathcart on Sunday, before he completes the final part of the route into Bombala on Monday morning.

There he'll be joined by a detachment of Bombala High School students while local police will provide an escort as the group jogs into Bombala at about 9.15am.

To sponsor Denis Reid in his bid to raise $10,000 for MS NSW/ACT, go to http://www.everydayhero.com.au/event/my-personal-challenge and follow the links to donate.