I quickly realized that OKC was really not well-suited to my specific purpose (as I feared), but I have met my more general goal of finding more people who place a high value on physical fitness. Several of the people I've connected with so far are avid cyclists, for example. My own bike is rusting on the balcony, but I have great respect for cyclists (especially those brave enough to deal with the traffic around here).
While emphasizing that I was not looking for a sex partner or primary relationship, I did leave the "long-term relationship" box checked as a possible option. I don't expect I have the bandwidth for another serious romantic partnership alongside boyziggy and Ben, but I prefer to allow each relationship to grow naturally rather than arbitrarily closing off any possibilities. I certainly wasn't looking for another long-term sweetie when I met Ben.
So we'll see where this goes. It's good to expand my social circle regardless.