I've been on board here since I started marathon running 5 years ago. I just completed my eighth marathon and plan to do more but many people I talk to say that it has adverse effects on your body, especially joints. Granted most of them are not marathoners but are good atheletes so it made me wonder. Those of you who have been running marathons for awhile what do you say? Do you feel that the sport has helped you or hurt you physically or made no difference?