I was running on a wooded trail amid rocks and roots this week when a gremlin yanked my foot. I pitched forward, grabbed the air, and braced for a knee-scraping, wrist-breaking fall. My toes dug in, my legs churned, and miraculously I wobbled upright. I came to a safe stop with my heart thundering.

Then I went on running. This is what runners do: We keep going despite fatigue, calamity, and fear of what might come next. And we are doing it in unprecedented numbers.

According to RunningUSA, about 54 million Americans went for at least one run last year. Around 30 million do so on a regular basis. Every weekend, thousands blast down race courses in polyester shorts, shiny shoes and shirts that say things like “I may be slow, but I’m ahead of you!”

Some slide along like quicksilver rabbits. Others surge and gulp like stranded carp. I like them all because they take on challenges, rip optimism from the jaws of despair and keep standing up no matter what tries to put them down. Runners are Republican, Democratic, Independent and unaffiliated; conservative, moderate and progressive. They are black, white, brown and mixed; Christian, Muslim, Jewish, Hindu, Buddhist, agnostic, atheist and undecided.

And they did not blink in the face of terror. They stood together.

After the Boston Marathon bombing, the races kept rolling. Runners kept gathering in welcoming herds, wearing ribbons for the victims, nodding respectfully to each other as the start was called, silently saying, “While we have to mourn our losses, we do not have to sacrifice our freedom. We do not have to live afraid.”

I know it’s a little thing, but it meant something to millions coast to coast: runners who will take to the roads, tracks and trails again this weekend in glorious freedom, while the marathon bomber — guilty on all 30 counts — will never run free again.

Tom Foreman is a CNN correspondent and author of the upcoming book “My Year of Running Dangerously: A dad, a daughter, and a ridiculous plan.”