In my experience, long-distance runners feel a kinship that only people crazy enough to run to the point of stumbling, dry-heaving incoherence can. So when two explosives killed three people and injured more than 170 near the finish line of "the runner's Holy Grail," as four-time marathon veteran Jim Bullington described it in The Nation, I had no doubt that runners would show solidarity with the affected marathoners and spectators of the Boston Marathon.

What I didn't expect was for it to happen so soon:

Not that I, or any other runner, should have been surprised. "This is a very tight-knit community, very much a fighting community who is extremely resilient," Chris Farley, a running store owner in Boston for the marathon, told USA Today. "You have to be resilient to be a distance runner."

Resilient or not, the events of April 15 will no doubt weigh heavily in the minds of future marathoners. Steve Spalding of the Detroit Free Press laments the loss of innocence in a sport that was, for many people, a respite from exactly the kind of horrors that occurred in Boston:

I've been running most of the last 30 years. I've never felt bad after finishing a run, no matter what else was going on in my life and the world.

Running makes friends of people of all ages and political beliefs. But not even running a race can escape the terror that has spread to seemingly every aspect of our lives, joining flying on an airplane as something that will require increased police presence. [Detroit Free Press]

Aside from the psychological toll on runners, there are now a new host of practical problems that will plague race organizers who are tasked with keeping people safe. Of course it has never been possible to completely secure every foot of a 26.2 mile race in a bustling metropolis — but they go on. And in London on Sunday, some 35,000 runners will make their way through a city of more than 8 million during their own marathon. CNN reports that the London Metropolitan Police will be stepping up security and coordinating closely with race organizers.

Still, as necessary as these precautions are, there's only so much you can change a marathon before you alter what makes it special, writes Roger Robinson writes in Runner's World:

Could we run marathons on safe closed circuits? How could you reconcile that with the essential notion that the marathon is a journey, and a celebration of the community or the environment it passes through? I just received a press release from the London Marathon, where I'm due to travel tomorrow morning, to say they are "reviewing security arrangements with the Metropolitan Police." How do you reconcile that need and that language with the essential innocence of the marathon? [Runner's World]

On social media runners have remained resolute in the face of these new challenges. The main response to the Boston bombings from athletes prepping for the London Marathon wasn't one of fear or cynicism, but one of quiet, stalwart support:

For marathons to exist as they are — open, joyous celebrations between athletes and spectators unlike anything else in sports — organizers cannot move them to private locations or line them with battalions of security personnel.

Runners, and the people who support them, will simply have to be brave. Arkady Hagopian, a marathoner from Los Angeles, finished the Boston race 10 to 15 minutes before the explosions ripped through the crowd and turned the finish line into what some witnesses have described as a war zone. "Whoever did this is trying to break people's spirits, but it's not going to happen," Hagopian told The Huffington Post. "I was on the fence, but now it's definite. I will sign up next year."

As Kathrine Switzer, the first woman to run the Boston Marathon, once said: "If you are losing faith in human nature, go out and watch a marathon."