The older and achier I get, the more it takes for me to maintain a running practice. For example, I actually stretch (sometimes) now. There's also a mental component to staying in active; I find inspiring places and run them. This place in Pacifica, Calif., provided both inspiration and some cool places to do yoga. Thanks to my Brooks shoes for handling the terrain, Icebreaker top for keeping me warm in the sea breezes and Under Armour tights for being tough enough to handle to rough surfaces.
Small tip: when combining yoga and running, start with a bit of running or a hike. There's a risk of injury if you stretch before warming up.