Posture

The other night I was walking through the neighborhood, and I saw a jogger coming up the road.  It was getting dark, so I couldn't really make out anything except the outline of the person.  I noticed the person's posture was less-than-great, and so I guessed that it was an older runner.  As the person got closer, it turns out I was right.

Posture really seems to take a nose-dive during aging.  If you compare a college-aged recreational runner to a jogger in their 40s, the difference in posture is dramatic.  I don't know if resistance training alone is enough to maintain good posture through the years.  Perhaps some other special exercises are necessary.

Does anybody have any good resources on posture?  I have a Paul Chek book somewhere in the basement, but that's about all I've got.