We run because dogs love it, and it is so good for them. Most dogs need about 45 minutes of physical exercise per day and about 15 minutes of mental exercise (training) per day. Regular physical exercise keeps their joints, bones, heart, and lungs healthy. We agree with the mantra that a good dog is a tired dog. Walking is great exercise, but when it comes to burning off excess energy or shedding excess weight, running is superior to walking.