I walk more lately. Last summer, I changed my exercise routine so that I walk four miles most weekday mornings. I leave early, usually before daybreak, and trek from the Park View neighborhood to downtown Harrisonburg, Va. I walk the sidewalks, varying my route each day. Irene, my wife, and I also walk more together than we used to. When we’re in the mood for ice cream at Kline’s, or supper at Little Grill, we’ll walk the several-mile round trip rather than drive. Once we joined 150 others in the CROP Walk downtown …