Hi !!
I too have dogs to walk but I think the length and the style of walk really contributes. If I stroll along enjoying the scenery , nothing happens - but if I do at least an hour, with attitude !, i get a good result in the readings department. Anything between 10 - 30 minutes appears to be insignificant for me. We're all different though.
But your 6s and 7s sound great!! :thumbup:
CathyN ( 1 collie puppy, 3 elderly collies, 1 greyhound , 1 lurcher ) :crazy: