You are correct, There is a difference between a active fit and dog and an over weight dog. On the flip side there is a lot of difference between that same active and fit dog and a dog at peak. A dog can be lean, fit, active and in shape his entire life and that is a healthy lifestyle. A dog can't maintain peak for lengthy periods of time. A dog at peak for a length of time will quickly become stale. It needs to be some sort of release and rest after that much work. EWO