A few miles a day at a good pace puts some proper stamina into a dog , Not something every body can do though . I try to get mine out behind my bike i have a bit of bike track 0.8 miles i do this at around 15mph . It does help , but is not the be all and end all . you can get a dog ready from plenty of work . But in all seriousness how fit is fit enough ? I dont go out hunting half as much as i did and i dare say most people on this site are not out doing as much as a small percent ! . Mine catch gear everyday of the week pretty much through just walking them after/before work and are fit eno