Originally Posted by BikeWNC

I bet those top marathon runners will not be running those weekly totals when they are older. Some of those guys suffer chronic fatigue like symptoms later in life, like they wore their body out. Running takes a toll on the orthopedic structure. No way could I run even 20 miles a week with my back, hips or knees they way they are. Cycling is about the only aerobic yearround activity I can do. Everything in moderation, but try to stay consistent in one's participation is a good goal to strive for.