The length of exercise will depend on the dogs energy level. If he is displaying unwanted active behaviour, his exercise amounts may need to be increased, until a suitable level is reached. You can also change the type of exercise that the dog receives, by using playing games, letting the dog off the leash (in appropriate areas), swimming, agility classes, etc. It is generally better to take the dog out at least twice a day or follow a routine. Puppies dont need to be encouraged to exercise. However, you have to be careful not to over-exercise them because their bones arent very strong. The rule is to exercise them a little and often. Middle-aged dogs may need more encouragement. Its up to you to make sure he gets regular exercise through his middle years, which will help keep him to his proper weight.
Question by - Krishnan Ravi, Nellore