I am above 50 years old and struggled with my knees when running more that 1km at a time. Started cycling (and spinning classes) July 2009 and taking it easy and "nursing" my knees. Now my muscles and ligaments have adapted and I can put serious strain on them during uphils with not problems. Cycle on the road. Have read somewhere that cyclists should also include running in their training program because the shocks, relative to the fluent movement of cycling, are actually good to increase one's bone strength. Cyclists tend to have weak bone structures in their legs.
