PacoG, I hear you. Why does your doctor say you have to stop riding? Is it because of the danger of crashing? Or would it be OK for you to ride on low-risk trails and roads where the likelihood of crashing is small? I'm 73 years old, with pain all over my body. But the cycling actually reduces the pain. I go on safe roads, local traffic only, with an average speed of 12 to 13 miles per hour (19–21 kph). Works for me. Doctor says to keep it up.