Ancaster's Richard Greidanus, who died after collapsing near the finish line of Sunday's Road2Hope Marathon, was an experienced runner who had successfully competed in many long distance events.

Race co-ordinator Gord Pauls had trained with Greidanus, who most people knew as Rick, as part of a running group based out of the Runner's Den in Hamilton for the last 10 years.

"His outlook was always so positive, he was always smiling," Pauls told CBC Hamilton.

'His outlook was always so positive, he was always smiling.' - Gord Pauls, Road2Hope Co-ordinator

"He always worked hard at his running and was very systematic in his approach," he said, adding one season Greidanus had worked tremendously hard to qualify for the Boston Marathon, a lofty goal shared by many runners.

He'd also finished the 30-kilometre Around The Bay road race multiple times.

Greidanus's athletics, however, didn't define him, Pauls said. His caring, kind demeanour did.

On Monday, staff at the Runner's Den were visibly shaken up by Greidanus's sudden death. The runner fell just 10 metres from the half-marathon finish line, after 21 kilometres of running.

Healthcare professionals immediately performed CPR before he was taken to hospital, but was pronounced dead there. The exact cause of death has not been released.

Richard's wife, Joanne, was also racing on Sunday but was further back in the pack when he died. The pair often ran together and once competed in the Around The Bay race as a two-person team.

In an email to CBC Hamilton, Joanne Greidanus thanked those who were at her husband's side at the finish line.

"We take great comfort in the fact that Rick was doing what he loved, that excellent medical care helped immediately, that people who knew him and loved him were nearby," she wrote.

She also said her husband was a Christian, "and we know that he is with God."

At the Runner's Den, calls from Hamilton's close-knit running community have been pouring in.

"Everyone wants to be of help," Pauls said, adding with the family's blessing there might be a run honouring Greidanus in the future.

Outside of running, Greidanus worked as a controller at Sobotec Ltd. in Stoney Creek, a job which his wife says "he absolutely loved."

Cardiac arrest often to blame in marathon deaths

In most marathon deaths cardiac arrest — the deadly condition when the heart stops beating — is to blame.

'There's nothing in life that brings things down to zero risk.' - Dr. Robert McKelvie, Hamilton Health Sciences cardiologist

Dr. Robert McKelvie, a cardiologist with Hamilton Health Sciences and McMaster professor who specializes in heart failure, physiology and exercise testing, said it's possible an underlying heart condition likely caused the runner's collapse.

"A lot of these guys that are avid runners … may not have been as physically active for their entire life," McKelvie said, noting disease starts accumulating in the coronary arteries in your 20s.

"Most times with people in this age group, it's usually coronary disease that's the culprit."

McKelvie said it's a good idea to get checked out by a doctor before embarking on a running program.

But, the scary thing for runners, is that these "occult" heart diseases, as McKelvie calls them, don't necessarily impair a runner's performance or even present symptoms. He recalls treating an Around The Bay running race competitor who raced to a fast time and then collapsed in his office two days later.

Overall, being physically fit reduces the risk of heart disease. But it can't stop tragedies like Sunday from happening.

"There's nothing in life that brings things down to zero risk," McKelvie said.

Male runners at greater risk: study

New York City Marathon

While running is good for the heart, even elite runners can't completely eliminate the risk of cardiac arrest a Hamilton heart doctor says. (Kathy Kmonicek/Associated Press)

Among runners and race organizers, the risk of cardiac arrest is known but marathon deaths are still shocking. At last year's Road2Hope a runner collapsed near the Confederation Park finish line, while multiple runners have died over the years at major marathons like Toronto, New York and Chicago.

The RACER study, a widely-cited 2012 report in the New England Journal of Medicine, laid out perhaps the best analysis of cardiac arrest in long-distance running races.

The study found there were 59 cases of cardiac arrest (40 in the full marathon and 19 in half-marathons) among the 10.9 million registrants in U.S. races from 2000-2010. That's one cardiac arrest per 184,000 racers. Of those who suffered cardiac arrests, 42 died.

Men were far more likely to suffer cardiac arrests than women, while the average age was 42-years-old.

The incidences of cardiac arrest, the study found, spiked in the fourth quarter of the race. The study also found that late into races fewer people were able to survive a cardiac arrest.

According to Heart and Stoke Canada, there are up to 40,000 cardiac arrests each year in Canada — one every 12 minutes — most of which result in death.