"It is always better if the dog will go all out because he simply wants to do so." Yeppp.

I guess my pet peeve is if you have a dog that will pull/run while handwalking and the owner still put the dog on the mill (at trotting pace, not sprint/sprint intervals) after the roadwork. It's like asking a runner to hop on a treadmill after doing his long distance run, just doesn't make sense.