A lot depends on the condition your dog is in,
This and age are really the determining factors. I training my labs throughout the off season but starting about three months out, they are drilled daily on multiple blinds until their morning routines are seven blinds, one after the other.
They have been trained to run blinds, no dog trotting, pigging it or walking, thus by this time of the year they are doing what equates out to wind sprints for about 1.6 miles for the younger dogs and about 3/4 of a mile for those over eight.
Afternoons are dedicated to water marks and handling drills. The younger ones swim about a half mile each day, the older ones about a third of a mile.
I have conditioned them this way for years. I hunt each dog as much of a day as we hunt ourselves and then rest her for two.
This year will be managed differently than the past years. I am now seventy and all day hunts don't hold the attraction for me any longer. I am also down to six dogs, three of which are now old enough for one to be hunted a half day and the other two for no more than an hour, maybe two.
For those of you who do not know, I own Yellowstone Kennels in MT and have enjoyed the advantages of very good training grounds and the time to put into the dogs' conditioning. My guidelines are not practical for most and I outlined here, my answer to the question asked.