So, yesterday on a nice easy run I turned off of a road with a decent incline and onto a walking trail. I stopped to stretch a bit when along came a couple (apparently male and female, apparently married) about 60ish in age, thus being just a few years older than me. As the couple walked past me the man said, "You should do ten sprints on that hill". My first inner reaction was "what's it to you?", but I actually responded that I had done that workout in the past (admittedly, not a bad workout, which I had done in the past). However, the man had no knowledge of my ability. As we went our separate ways, I thought about the interaction, and considered whether the man could even do the workout that he suggested that I do. I thought about whether I should have asked him if he could do the workout, or whether I should have challenged him to a contest on the hill to prove his manliness in front of his women. The whole thing kind of bothered me because all that was needed was a simple greeting, but the man for some reason took things beyond that. How would you respond to such unsolicited training advice?