I looked on the internet to find out the temperment of breeds of dog - I wanted one that could run, but would be good with children. I had a collie and a Labx before, but the collie breed needs lots of work to keep them occupied and I found they could be a bit unpredictable with children. The Labx was fine, but they do get hip problems. I decided to go for a pointer and got one from a rescue organisation for that breed. He was great to run with, apart from a tendancy to dash into bushes and maybe ran a bit too fast for me to keep a good eye on him. But he had other problems and basically ate my kitchen when I left him alone even for 10 minutes. In the end I decided on a cocker spaniel, being a working breed, they can run and are more managable. I got an 8 month one who was a reject from a show ring and he has been really good. I had to start slowly, as he had never been off his lead. The vet said start him at 12 months, although I confess to taking him before then as he spent all his time running anyway, even if I was walking. I run off road. The vet said that from 18 months he could do anything. Now he is able to run for an hour easily and has done 1 3/4 without a problem. He also comes with me if I go on the bike, although I make sure he is in front of me, or slow down until he catches up. He does have a tendancy to go into rivers and also to look for rabbits.