My Kelpie Brodie has plenty of energy and he's only 7, but I don't see that ever changing with age. He could go for five walks a day and he could run for miles if I had the energy and fitness to keep up with him. He lives with my ex currently, who has a big backyard and he gets to go for a run in the reserve at least once a day. I used to think it was because of the breed he was, but then I have met people with Kelpies and other working breeds whose dogs prefer to laze about all day. Some won't even chase a ball which is strange for a working breed. I think it somethings depends on the individual personality of the dog.
