The answer to the question lies within another. Is running your lifestyle, or is it your hobby?
For me endurance sports is a lifestyle. It doesn't pay the bills (aka: a job) but when I'm not locked between 4 walls I can be found, with little exception, running, biking, or swimming. If I had been inclined to date a non-runner we would likely never cross paths. We would be ships passing in the night. Rather, I met my husband while running. He sold me my first pair of custom fit running shoes and invited me to travel with a group of runners from our town all racing the Chicago Marathon.
I admit, we take running to the next level. Wedding? Vegas marathon run-through ceremony, of course. Honeymoon? Ironman World Championship in Hawaii. Vacation? How 'bout a week in Pebble Beach following the Big Sur Marathon. Or the Tahoe Rim Trail Ultra with some bonus days in the mountains. It's our passion.
Without him I'd still be passionate about running, but it's soooo much better to have someone to share it with, someone who gets it. We get to laugh over a post race beer about things that happened during the run. Our favorite spectator's sign running through Wellesley College. Where on the trail I took a wrong turn. How I missed a PR by 9 seconds because I had to stop and tie my shoes.
A non-runner would have to listen to my stories, but just wouldn't get them. I would feel sorry for him. I would feel guilty spending all my time on the trails and not with him. He would start to feel resentment. We would fight about priorities. Eventually it would end tragically, hopefully prior to any legal commitment. We would both turn to our passions to mend our broken hearts. I'd run twice as much in an effort to forget the pain I caused and endured. I'd end up injured and have to take time off from running furthering my mental anguish....
No, no. It's better I just stay far away from non-runners. Nothing good can come from that.