Great article Antonia and most certainly true, our bodies need movement. I have never really been a fan if walking, always a runner until the last few years when we got a dog. I must admit that view has now changed for all the reasons you describe. It's surprising how mentally refreshing walking can be and the amount of energy you burn with a steady pace. It's pleasing to know for as long as your muscles and joints hold up as a low impact form of exercise. It is something potentially you could do well into old age.