Another component of your dog's overall temperament is his energy level. Some exuberant dogs can be a challenge to control physically. High energy dogs are often selected by professional dog handlers and law enforcement agencies because their energy level will be required to withstand the rigorous life of a working dog. Sporting and Herding dogs are known for high energy levels. 

Low energy dogs can also be a challenge to train. Motivating them to exercise sufficiently and keeping them interested in obedience lessons may not be easy. These dogs make wonderful pets for a busy family. They are not disturbed by constant activity and changing schedules. Some hounds and guard dogs are known for low energy levels.  

Most dogs fall somewhere between the two extremes. You may not be able to evaluate the true energy level of a young puppy at nap time or a dog in a shelter or other stressful situation. Make more than one visit to evaluate a dog you are considering adopting. You may get some insight into your dog's energy level by comparing his activity to that of other dogs you know well. 

To fully evaluate a dog's temperament, be sure to read about IQ, social status and responsiveness.