My partner and I rotate three dogs through the day, a different dog each hunt. We can go two weeks with out burning out dogs. I can do about 5 hunts and the last two a day I drop my partner off and wait for him at the other end of the hunt. I'm getting old, old enough to be his father and remember seeing the first Howdy Doody show.
A lot depends on the condition your dog is in, right now I'm walking about mile and a half with my dog off lead working the field and doing retrieves and them down to the lake for a few water retrieves. He's about ready we start in a week. I still feel like crap when we get home.