You're never too old to run a marathon.

At 101 years young, Fauja Singh is the world's oldest marathon runner. He's competing in the Mayor's 5K Run at Sunday's Surrey International World Music Marathon.

"It's not me who decided to start running, it's my God who decided for me," said Singh in Punjabi, translated by his granddaughter, Simmi Dhillon. "I'm helping a lot of people out, donating whatever I gather from these marathons to charities.

"At this age, it's not like I'm someone who can hold a job or even run, but I'm running."

Singh was born in 1911, before the First World War, and is from Bias Pind, a village in the Jalandhar district of northwest India. He presently lives in England and recently flew to Canada to visit relatives in Surrey.

While Singh couldn't remember how many marathons he's completed or how many kilometres he's run, he did say he's only been running for 16 or 17 years - meaning he started running in his mid 80s.

"He watches what he eats and he walks about four to five hours a day," said Dhillon of the secret to his longevity. "All his focus is on his eating, his health."

Singh said he's completed the Toronto marathon in four-and-a-half hours, but he doesn't concern himself with how quickly he competes the race.

"It's not about the time now for me," he said. "It's just all about, 'keep going.'"

He admitted that because of his age, he has worried about his health on the track, but said his faith motivates him to make it to the finish line.

"What if I walk out of the race and a bus hits me?" he said. "I'm going to die regardless, so why not die on the track doing what I love to do?"

The Surrey International World Music Marathon is this Sunday, with the full 42-kilometre walk/run at 7: 30 a.m., the half-marathon at 8 a.m., the Mayor's 5K Run at 9: 30 a.m. and a one-kilometre Kids Fun Run at 11 a.m.