Yesterday I walked to The Heath and back as I wanted to go to the butcher.  A while ago I got really out of breath doing it, so I haven't tried for a while (the weather hasn't helped, of course)  The "through the woods" way is decidedly squelchy so the trip there and back takes about 1/2 an hour the longer way round.  And I did it and I felt fine!  I am going there to church today so maybe I will do it again (if it isn't raining)