I first heard about the explosions at the finish line of the Boston Marathon when I was changing to go for a run. In the track locker room, I heard one of my teammates on the phone, telling a loved one to stay calm — the ends of marathons are always chaotic, he said, and it wouldn’t be possible to find out what happened right away.

I was already in my running shorts, but I reached into the pocket of my jeans, pulled out my phone and searched for news about the Boston Marathon. Eventually, I found a tiny blurb on the New York Times home page: Two explosions were heard near the finish line. I went out to stretch.

They were talking about it at the track when I arrived. Some of the guys had brought their phones out there, and the team huddled around the tiny screens in between stretches. We learned that the explosions had knocked people down, and that some might even be injured. But that was all we knew. I stretched, feeling my body ache with each movement. I had run hard the day before, when a teammate and I had raced the last mile of our 16-mile run. I could feel it today, especially in my calves, which burned as I pressed my feet against a ledge. It would be wrong to say that the mood was solemn, but a nervous energy emanated from the tiny phones. More jokes were made than usual, but we laughed to keep away the silence. And then we went on our run.

Runs have a subtle choreography to them. You feel yourself in relation to others more acutely. Individual runners fall back and move forward, but the entire group responds dynamically. Being half an inch ahead of the runner next to you gives you control of the pace, and when you fall back half an inch, you cede control to your partner. When done correctly, everyone controls the group for a moment, so that the group as a whole is in charge.

The same is true of a marathon. Not up front, where prize money can be won. There it is cutthroat. But in the middle of the pack, the race takes on a different dynamic. There, the race is not so much about beating your fellow athletes as it is lifting each other up to the task. Twenty-six miles is a long way to go alone, and the subtle dance of half-inches creates an impromptu community that supports runners through the lonely streets and heartbreaking hills.

By the fifth mile of yesterday’s run, I found myself with only one teammate beside me, the captain of the cross-country team, Kevin Lunn ’13. We loped through the forest paths together, talking about running.

Kevin observed that the world is different after a run. The colors are more vibrant, the air is crisper and the worries of life fall to the side. If the world is different after a run, he explained, there must be some point during the run when the world undergoes a transformation. There must be some point, perhaps seven miles in, when the world is remade before our very eyes and we do not even notice. Perhaps the pounding of our feet reshapes the earth beneath us; it is beaten into new shapes that mirror the old ones, but are sharper and purer. It is impossible to run the same path twice because with every run, we destroy the world and then create it anew.

When Kevin and I arrived back at the track, the team was huddled around the screens again. I heard someone say, “Two dead, dozens injured.”

Running is not an escape. It is a confrontation. It is a refusal to accept the world as it is and an almost naive insistence that work can change things for the better. It is a refusal to accept terror. That is why I, try as I might, cannot view this marathon as a tragedy. A tragedy is irredeemable, but the events of yesterday have already been redeemed.

Every runner who kept running up the hills, only to be finally stopped by police barriers, has redeemed this marathon. The runners who went to the hospital to donate blood have redeemed this marathon. The Kenyan, Ethiopian and American elites who have trained their whole lives to compete at Boston have redeemed this marathon. And, in their little way, runners all across the world who heard the devastating news but still laced up their trainers and put on their shorts have redeemed this marathon. Terror may break the world, but running repairs it.

Isa Qasim is a sophomore in Jonathan Edwards College. Contact him at isa.qasim@yale.edu .