Border Collies do have great stamina. When we run, they focus on the run and hardly notice when we pass other dogs. I also have a dog back pack. I carry two waters and a collaspable bowl. They get watered along the way. On days we run off trail, they stop and smell what ever and then run to catch up with me. When we get home from running, they bring me a ball or something to play with. I'm pooped, and they still want to play. I just don't want to be unaware of any hidden dangers to running so much with them. Like I said, they will be running no more than 1 and 1/2 hour 3 days a week, with their walks in between. I think I will be able to protect them that way.