I just started a thread about walks the other day
http://www.yorkietalk.com/forums/gen...ily-walks.html
Jackson typically goes for a 1 hour walk per day (all at the same time). The farthest we've walked at one time is about 5 miles and he did that easily... and came home and was still ready to roll.
A 1 hour walk will tire him out and he'll sleep for about 2hrs coming home... but walks definitely don't do as much for him as running, or swimming, or other strenuous activity. He gets a 2hr dog park visit about once a week where he runs a TON, and he gets to go to my dads huge fenced in yard with his 2 dogs about 2-3x per week where, again, he runs like crazy! And in the summer, he swims a whole lot!