Exercise is important for any dog. A dog that doesn’t get enough exercise quickly gains weight and may become extremely keyed up or very lethargic. Fortunately, most dogs love to exercise by nature. They love to run and play with their people. The overweight dog my be reluctant to exercise at first, but if you persist in taking him for walks or to play games like “fetch” (most dogs love to run after a thrown tennis ball or other object), the pup will soon come around and start exercising more frequently and for longer periods of time.