Why?

Here's an article on people and their continuous running streaks:

http://sports.espn.go.com/espn/eticket/story?page=streakrun

As 1992 US Olympian PattiSue Plumer said at the USATF National Podium Project seminar in Las Vegas, the miles you run must have a purpose.

Please let me know what the purpose of running every day for 30+ years is...