Can just walking give you enough physical activity?

I walk all the time. I don't like running and I never have. I always hurt my legs and everything like that, but I love to walk. I can walk instead of catching the elevator. I walk down the steps everyday at work and I walk up. I park my car a ways back and I walk. I do have a bicycle and I'm going to ride it this year. I learned how to ride a bicycle after forty-some years, and I'm going to ride my bike and I'm going to walk. I do like walking.