All dogs should get as much exercise as possible. A daily walk is sufficient for most breeds. But most small dog breeds, for example Toy dogs such as Pugs, Maltese or Yorkshire Terriers, will get the majority of their required exercise needs just be walking, running and playing around indoors.
Your dogs temperament should match yours. Do not choose a breed that is highly energetic if you are a couch potato. On the other hand, if you want a dog that will follow you everywhere around the house and who is always ready for a game of fetch or tug of war then you should consider a dog that is highly active and always has a lot of energy, instead of one of the lethargic breeds.
Dog breeds are dogs that have relatively uniform physical characteristics developed under controlled conditions by humans, with breeding animals selected for phenotypic traits such as size, coat color, structure, and behavior. The Fédération Cynologique Internationale recognizes 337 pure dog breeds. Other uses of the term breed when referring to dogs may include pure breeds, cross-breeds, mixed breeds and natural breeds.
If you do not have time to exercise your dog daily with a brisk walk and lots of running choose a breed that does not have high exercise requirements. All of the breeds who require high amounts of exercise make terrific jogging, hiking, and ridding companions. So if you want your dog to accompany you on long runs choose one of these highly active breeds built for endurance and as much exercise as you can throw at them - they will love you for it (and a tired dog is not destructive).