Tommy Des Brisay, 22, was diagnosed with autism at an early age, but that hasn't stopped him from winning countless racing medals or from clocking a half-marathon race time of 1:14:55.

On Sunday, Tommy laced up on Ottawa Race Weekend for his first ever marathon. And despite the much longer course, his focus remains the same as it has been since he first started running eight years ago.

LISTEN | Tommy talks about his first marathon

"Determined to win the race, win my age category," said Tommy.

Tommy wasn't always an athlete.

When he was five years old, experts told his parents, MaryAnn Given and Peter Des Brisay, that he may never develop the ability to speak.

By the time he was 14 years old, he was overweight as a result of medication he was taking, and his parents wanted to find an interest for him to pursue.

Hooked on running

Tommy proudly shows off his collection of medals. He has won races for running, kayaking and cross country skiing. (CBC) MaryAnn suggested to her husband Peter, who was a regular runner at the time, to take Tommy out on one of his runs.

"We started thinking, you know, maybe Tommy could go with him on his jogs. And the first time out, Tommy was a very different guy than he is now … he was overweight, he was not fit. He was a guy who could probably run a couple hundred metres then needed to walk for a bit," said MaryAnn.

"My dad and I went out for a run for 3 K on Wednesday August 2nd, 2006," said Tommy proudly.

After that first run, Tommy was hooked on the sport.

In his first year of running, Tommy trained regularly, lost 35 pounds and started to develop a muscular physique.

Tommy signed up for and started competing in a variety of road races, sometimes taking first place in his age category.

"I run every day, every week, every month, every year," he said proudly.

One of the gang

Over the next eight years, running became part of Tommy's daily routine.

"It became a different way to help Tommy with his anxiety to give him a positive outlet for a lot of energy he had, to give him opportunities to feel good about himself and feel healthy," said MaryAnn.

His father Peter has dedicated hours to coaching him and he cycles alongside Tommy giving him words of encouragement on long training runs.

Peter Des Brisay bikes alongside Tommy and coaches him during his runs. (CBC) Tommy also trains with the Ottawa Lions Club three times a week and MaryAnn said being part of that team has given him true friendships and enriched his life.

"He has become part of the running community of Ottawa and that is huge … the Ottawa Lions Running Club have embraced him and supported him and accommodated him and made him just one of the gang," said MaryAnn.

"For Tommy it's been an amazing way to have his life head in a slightly different direction."

Organizers at Ottawa Race Weekend agreed to let Peter ride his bike and guide Tommy during his marathon on Sunday since Tommy can be unpredictable in crowds and needs guidance to follow the route.

Tommy looked forward to taking part in the run and hearing the cheers of the crowds along the route.

"I train to be the first fastest runner in the world," he said.