HE felt relieved.

The doctors had just told him he had multiple sclerosis. Yet he felt a burden had been lifted. "I did not know what multiple sclerosis was but it was not as bad as I feared," says Matt Piper, all of 33.

"The way I was feeling and the way the doctors were having a serious talk, I thought it would be a brain tumour or cancer. When I was told it was MS, I thought: 'This is okay. I can deal with this'."

It was March 6, 2012. "I hear people with MS say that the day they were diagnosed was the worst day of their life," he says. "It was not the worst day of my life. The worst day of my life was when I was 15 and dropped two catches in the county cup cricket final for us to go to nationals. That is still my worst day.

"I didn't get any runs opening the batting and the bloke who I dropped went on to make 50-odd and won them the game. I cried and I didn't go up for a medal. One of my team-mate's brothers took it. I don't want second place."

This is all said in one breezy burst but it the most compelling evidence of Piper's character. There is a light-heartedness to his words but they cannot disguise the deep competitiveness that not only lives with his MS but seeks to overcome it.

This battle is not about that cliched notion of "beating" a disease. It is about something far more profound. It is about accepting an illness but also refusing to be cowed by it.

Two years after his diagnosis, Piper will next month take part in The Rat Race City to Summit Challenge. He will swim 2.4 miles, take a 112-mile bike ride and run for 27 miles, the route taking him up Ben Nevis. He will raise funds for the MS Society but it is about much more than that.

Piper wants to be the MS Iron Man, the most visible frontrunner in a campaign to show that his illness has limits. It has its dreadful symptoms, it has its dispiriting prognosis but it need not define his life. Not today. Not now.

"I was always a fit guy," he says. "The diagnosis came when I was applying for the Royal Marines. I was then 30 and I felt I had done everything I wanted to do. I tried out for the Marines twice before so this was sort of a last chance saloon. I wanted to settle down."

A boy from Hemel Hempstead, Hertfordshire, his love of hill walking had led him to take the overnight bus from Victoria most weekends. He was a joiner but in 2008 the recession hit and he moved to Fort William to work in a hostel. He then met his partner, Margaret Willington, and moved to Perth to work as a self-employed joiner.

Then came the diagnosis after symptoms that included what seemed like paralysis of his arm and increasing problems with his vision. Piper tried initially to work through the illness, helping a mate out as a labourer. But it was unsustainable. "I had lost sight completely in my left eye. I was struggling with my speech," he says.

There have been relapses but new medication has kept most of the worst symptoms at bay and Piper has decided to go ahead with the City to Summit challenge. As a mere warm-up, he took part in the East Fife Sprint Triathlon which involves only a 750m swim, 22km bike race and a 5km run. Piper boosted this by cycling from his home to Cupar and back to take the bike element to 65 miles. "I finished 120th so I was satisfied," he says of that challenge earlier this month.

His ambitions after the City to Summit challenge are clearly defined. He has already completed the 10 in 10, the event that demands scaling 10 peaks in the Lake District in 10 hours. He now wants to take on the Seven Summits. This involves climbing the seven highest mountains on the seven continents: Mount Everest, Asia; Acongua, South America; Mount McKinley, North America; Kilimanjaro, Africa; Mount Ebrus, Europe; Mount Vinson, Antarctica; Puncak Jaiga, Australasia Continent; Mount Kosciusko, Australia. "I know of someone with MS who has done all seven but she did the first one before she was diagnosed, so that title is up for grabs: first MS patient to climb all seven," he says.

But how does his doctor view this extraordinary effort? "My GP is on my side," he says with a smile. "He says that if you can do it without it making you ill, then do it."

Piper is aware that such strenuous challenges may not always be within his physical capacity. He already talks of having "bad days, sometimes bad weeks even months".

"There are times when it does get on top of you. You can think: 'My life is ruined', and fall into self-pity. But I am still alive, still able to do things, the sun comes up in the morning and my girlfriend has stuck by me."

His partner is a carer and works with MS patients so the diagnosis has been particularly hard on her. Piper does not shy away from what may befall him but, typically, he uses it as a driving force rather than a barrier. "I want to do the most extreme things I can because I want to look back and say I did some cool stuff. Up until my diagnosis I took stuff for granted but this has brought my life into sharp focus.

"I want to have kids and if I end up in a wheelchair and they have to help me around the house I want to tell them: 'Your old man was not always like this. He did some cool stuff before he had MS and did some cool stuff when he had MS'.

"I know I may have to scale it back but whatever I do will be at the limit of what I am capable of at the time. I want to stretch myself."

His days now revolve around his training. He rises for a swim at 7.30am and then may have a run in the afternoon. "In the evening I do the bike and then a run. It might be an hour speed session for both, so I'm looking at cycling 22 kilometres and maybe running six to eight miles. I tend to do the bike and the run together because that is how it will be in the triathlon," he says.

There is no let-up in his preparations, no softening in his determination. "You can do stuff," he says of what he has learned. "Do it now." He is talking about himself. In truth, he could be speaking for all of us.

n To find out more about Matt's story or to sponsor him, visit bemsaware.org