Word of a patchwork of actions — from individual runs to larger group events — spread through Internet forums, social media and emails as many Canadians said nothing would stop them from continuing the sport they loved.
"This will unify us and keep us strong as a community," Sarah Vingoe, who ran the Boston Marathon in 2010, told The Canadian Press.
"Instead of running into our homes and locking the doors and being scared, I think it's bringing everyone together and reminding us why we go to these things."
The 34-year-old, who works for a Toronto advertising company, was in Vancouver for business Tuesday and knew she'd be unable to take part in a solidarity run organized by a friend at home. So she went on her own solo run.
"It was pretty emotional. I think I ran a bit harder than I normally would and got a bit teary," she said, adding that Monday's events, gut wrenching as they were, wouldn't stop avid runners from hitting the pavement.
"That fear is not going to let us not run anymore."
In Toronto, dozens of runners stood solemnly for a moment of silence, many of them bowing their heads, before taking off on an evening run that started from the grounds of the Ontario legislature.
Despite the grim circumstances, the mood remained hopeful.
The tragedy that played out in Boston "definitely hasn't deterred me, if anything it's gotten me more inspired so I hope that others feel the same way," said Gillian Tweedie, who organized the event.
"On a human level, I think it's really important for us all to feel connected and that we're part of something that's a lot bigger," she said.
Doug Smith of the Ontario Masters Athletics organization, who joined Tuesday's run, said the event was a symbolic gesture, one he hoped would resonate with those affected by the blasts.
"It tells the people in Boston, especially the runners, that we're there with them, it's one big community," he said.
Another event in Toronto was being organized by running coach Megan Brown, who planned to hold a candlelight vigil with her running team before the group of about 30 people set off on their training route.
"If we don't carry on with our purest joyful activities such as running I think it's only letting whoever was behind the actions yesterday win," said Brown. "We need to carry on with life, especially parts of our life that are joyful."
The Boston blasts have undoubtedly altered how runners will think about marathons to some extent, but Brown said that change wouldn't be a crippling one.
"We're forced to mourn the loss of our safety in some respects. No runner would ever say they fear their safety on a marathon course and now that's going to change forever," she said.
"But I think it's only going to strengthen our conviction for running and the human spirit."
Jochen Tilk, who had been at the Boston Marathon, made his way back to Toronto Tuesday relying on the kindness of strangers to make his way to the airport from a locked-down city core.
He admitted he was "terribly shaken" by the blasts but was determined to share his experiences at one of the Toronto solidarity events Tuesday night.
"For me it's important to go there tonight, it's important to keep running and I absolutely look forward to Boston 2014," he said. "The spirit of people is so much stronger than the fear those who were responsible for this are trying to instill."
Whether they ran on their own or in groups, it was clear many Canadians wanted to take to the streets to express their anger at Monday's violence and show their support for the victims of the blasts.
"I think everybody is in a state of shock and horror about this and I think today we need to go for a run and reflect on our values, and what's important," said John Stanton, founder of the Running Room, which co-ordinates running clubs across the country.
Stanton added that Running Rooms across Canada would be holding a moment of silence Wednesday night at 6 p.m. before runners embark on runs dedicated to Boston.
"We have to show people we're going to be strong and united against this kind of terrorism and carnage," he said from Edmonton. "Much like running a marathon, there will be high points and low points, but we've got to keep moving forward."
A call was also circulating on social media for runners to wear a race shirt Tuesday as they hit the streets to show their lasting commitment to the sport.
Meanwhile in Vancouver registration for the city's Sun Run taking place this weekend got a boost by runners who refused to be deterred by the Boston blasts.
Organizers said registration for the 10-kilometre event had already surpassed 45,000 runners, and the number is expected to climb. In recent years, the event has averaged 49,000 participants.
The refusal of a number of Canadians to bow to fear came as security was ramped up at all points of entry across the country.
"Our authorities are at a heightened state of vigilance, especially in respect of border crossings," said Public Safety Minister Vic Toews.
"We want to ensure that if someone would be using our borders to cross into Canada for any inappropriate reason that those individuals are detected."
Toews added that while he didn't think there was any need for Canadians to worry, the government wanted to "take precautions" and was working closely with American authorities.
Meanwhile, Heritage Minister James Moore said Canadians stood in solidarity with those in Boston.
"It appears no Canadians were seriously injured or killed in yesterday's attack, but that doesn't affect the fact that we are all heartbroken as Canadians," he said in the House of Commons.
"The prime minister and our government, we stand shoulder-to-shoulder with President Obama, the mayor of Boston and the governor of Massachusetts as they try to find those cowards who are responsible for this terrible attack."
Yukon MP Ryan Leef, who had finished the marathon before the explosions took place, said he planned to return to the event in the future in a display of support.
"The community and the state will rise above it and I think going back will signal that – that this kind of violence is not going to win the day or carry the day," he said in the House of Commons.
"Running is a sport of perseverance and will and it will take all of that over the coming days and weeks to rise above this horrible attack."
Three people died — including an eight-year-old boy — and more than 170 were injured in the twin blasts which rocked the finish line of the storied marathon. More than 2,000 Canadians were registered for the event.
The Canadian government sent two additional consular officers from Ottawa to help the consulate in Boston. Consular officials have been helping Canadians retrieve their luggage and other personal belongings from hotels under lockdown.
U.S. President Barack Obama said Tuesday the bombings were an act of terrorism but investigators do not know if they were carried out by an international or domestic organization, or perhaps by a "malevolent individual."
Police in some major U.S. cities were monitoring landmarks, government buildings, transit hubs and sporting events.
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