Musta been a running club or something

Yesterday, as I was entering my car after my run, I saw three cars with several people, and the people were all dressed in the same training clothes. As I drove out of the parking lot, I saw several more cars with occupants wearing the same training clothes. Altogether, I saw about a dozen cars. None of the people looked to be of high school or younger age. I wish now I had turned around and asked who they were. It would have been interesting to watch them train for a few minutes. I noticed during my run today that someone had used a black spray can to draw a short line across the asphalt of the path and to paint the word "POST" next to the line. I don't remember seeing that inscription before. It was about 1/3 mile from the parking lot.