Every breed can be trained to learn almost every command. However, some breeds learn a lot faster than others - making them a lot easier to train. These highly intelligent breeds pick up a command after only about five or six repetitions, they more often respond on the first time you give the command, and they remember commands even if they are not practiced often. They also learn commands even when the trainer is inexperienced and makes mistakes. So if you do not have a lot of the time to spend dog training, or you are the impatient type who gets frustrated easily, choose a breed which has a high ease of training rating.
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).
The study found distinct genetic clusters within modern dogs that largely corresponded to phenotype or function. These included spitz-breeds, toy dogs, spaniels, Mastiff-like breeds, small terriers, retrievers, herding dogs, scent-hounds, and sight-hounds. There were 17 breeds that conflicted with phenotype or function and these were thought to be the result of crossing some of the other phenotypes. As in a 2004 study that found 9 ‘ancient breeds’ to be genetically divergent, the study found 13 breeds that were genetically divergent from the modern breeds: the Basenji, Saluki, Afghan hound, Samoyed, Canaan dog, New Guinea singing dog, dingo, Chow Chow, Chinese Shar Pei, Akita, Alaskan malamute, Siberian husky and American Eskimo dog. Results also indicated that the Basenji had recent admixture with Middle Eastern wolves.
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.