We're getting together this Friday night with a couple of my friends from elsewhere in Colorado, as the husband is in town to run the half marathon I'm also running. Last May, at the age of 53, he ran a 2:58 marathon - that's better than a 7 minute pace for 26.2 miles. My husband, who is 57, doesn't run (much), but he has no problem tackling some of our hard mountain biking. So my reference for the fitness of a 50-something man is a bit different than that of the guys you talked with! But that's Colorado for you...

Congratulations on running being fun. That is a good thing! And the more you run 'easy', the faster 'easy' will become.