I live in a city, and the city has a great multiuse trail perfect for walking, running, cycling, or scooting, if that's your thing. When running past a person, I generally acknowledge them with a nod or smile. We are in such close proximity it would seem weird not to. On my run this morning, I would say about 50 percent of the people I ran past responded. There was no discernible pattern, except all the gray-haired ladies out walking gave me a big smile that frankly powered my run. Acknowledging other people out on the trail makes me feel like I'm part of a larger exercising community — like we are all in it together. What about you?