Some readers are probably old enough to remember Jan Brady’s lament in “The Brady Bunch” about the seemingly undue attention that her older sister got: “Marcia, Marcia, Marcia!” If common road race distances were the Brady family, the marathon and the half marathon would be Marcia, getting all the attention. (“Oh, you’re a runner? Are you training for a marathon?”) The 5K (and maybe the mile, although that seems to be less common as a distance) would be Cindy; you’ve got the popular couch-to-5K programs to transition couch potatoes into runners.
Meanwhile, the 10K is just … there. (Yes, there are couch-to-10K programs out there, but the 5K is the most popular racing distance.) But here’s why the 10K is the best racing distance: I love running, but “too much of a good thing” describes half and full marathons. 5K, on the other hand, while a great distance too, is a bit too short to be truly satisfying. It’s kind of like having a tasty appetizer at a restaurant and then being asked to leave. “The Brady Bunch” isn’t the right analogy; Goldilocks and the Three Bears is.