As with any of us in pursuit of something we are doing, a dog should enjoy what they are working on, look forward to it and share in the feeling of mastery of what they do.  There are a number of ideas and approaches in training dogs, some very harsh and demanding, some very passive, and then there is the way that actually reaches the heart and soul of the dog.  That's the one that is going to work best for the long term. Olympic athletes have to really want what they are working so hard to achieve.  They cannot be 'corrected' or punished into it; it comes from a genuine love.  Equally true for our canine counterparts.  At least something to consider in performance training or the family pet.