For the last 25 or so years, I've been jogging lightly, on the order of 2-3 miles a day, occasionally pushing that boundary. Then I started going to the gym with my wife, who's there for around 90 minutes when she has physical therapy. I've been pushing my distance up, to an average of around 4-5 miles, and filling the rest of the time with light weight work - and often getting out twice a day.

Now I have the sore muscles I remember from high school and college each fall as I transitioned from the "off" summer back to cross country. It's a good tired though - I'm enjoying getting back to the distance aspect of jogging. The funny thing is, the first couple of miles are the drudge part of the whole experience - it's only around the 3rd mile or so that I really loosen up and start to feel good. That's part of why jogging seemed like a chore for the last decade - all I was doing was the drudge part.