Laev and I hope to participate in the AD (endurance test) at UDC Nationals this year (weather permitting). The AD consists of a 12.5 mile run for Laev, followed by an obedience routine (I get a bike for the mileage!). So we've started conditioning.
We just returned from a several-mile ride with my sister and her dog, and I checked pads -- no real wear. I offered water on the run, but she only wet her tongue and was finished. She hadn't slowed down at all by the end.
But... after a few moments of being inside, Laev lay down and is now contemplating a nap. Her eyes are still open -- but she's lying still.
It can be done! She *can* be tired! Whew!