Pedaling Fool has advice I wish I had known 30 years ago. Exercise to prevent injury!
As a woman, you also need to do what you can to prevent or postpone osteoporesis. Talk to your doctor about this and read up on it. I have a friend who is 73 who has osteopenia and has broken several bones (hand, wrist, ankles). She still hikes and can go a good distance, but needs to be careful about falling. It might be worthwhile to get a bone density study. Hiking and weight exercises are good for preventing this.