Elizabeth - I find planning my walking into my day makes sure it gets done. For example, this morning I will start a load of laundry, then join my friend for a walk through our bird sanctuary. Some of my walks are very short - it all depends on my breathing. And I learned the hard way last summer to do my therapy (stretching) before I go - had to stop halfway one day and do it on a neighbor's bird-watching bench...
I can tell exactly which days I skip walking at all, I feel fidgety in the evening and don't sleep as well.
Sue