A while ago we started running again too after a stop.Inar goes with us because we like to walk in an area with no people.Inar loves it as long he can runn trough the woods like a maniak.So fast that sometimes i think he come out with damaged eyes :D but nothing of that.So indeed they love it and funny that i read the same about yuor friends dog that he stays off the path but very close because inar does the same. I) havent tried it on my bike but i guess he fallows easily off lead trough the woods.On leash no way i think he block me everytime he wants to see something and that is very often. We runn but not much much harder than we walk :D just started again and it is more difficult for us to get a good speed than for Inar.