Mine NEVER tires either!!! However I have figured out that if I make him work he does tire 🙂 I use a backpack & it's great & has worked wonders for tiring out our crazy dog 😃 😃
Here's the one I got & I fill it with a couple of bottled waters (no more than 2lbs) and THEN we go out for 3 miles 😃
http://www.ruffwear.com/Approach-Pack-trade-II?sc=2&category=13
I also have a treadmill at home that I'm trying to get him used to so that he can do some extra work there too!
I can't ride a bike but there are some people on the forum that do bike with their dog for about 6 miles & they use this contraption 😃
There are ways I PROMISE you…we just have to outsmart them!!