Kennels size

I have had 6x12, 5x12, 5x10, and 4x8, and if you are only putting one dog in per kennel there is no difference in their activity level that I saw, your consideration would be how often do want to have to clean kennels. To me kennels are not for exercise they are just housing and I clean kennels everyday so I prefer 4x8 if I am only putting single dogs in. I have a routine that I do everyday in which I let the dogs out to run around while I clean the kennels and water and feed. So they are out of the kennels 30-45 min everyday and I hunt them once or twice a week during summer and more when it cools off.

If you are looking for activity then cable runs are the way to go, with chain setups being a runner up. Like T dog said they will be far more active on those than they will in a kennel. Some dogs will keep themselves in decent condition themselves on cable runs.