16. Brittany Spaniel
Get ready for that pleading look that just says, “I want to go outside!” Brittany spaniels are eager-to-please, very smart, and very energetic—they need lots of exercise, more than just a walk around the block. Leggy and light boned, these hunting dogs are quick and agile. “We had a Brittany for 12 years, and he was the greatest dog that I have ever had,” says one commenter on LetsRun.com.
15. German Shorthaired Pointer
German shorthaired pointers are true endurance athletes; they require regular exercise every day. Thanks to a lean build and muscular hindquarters, this breed is great for long runs (more than ten miles) and even keeping up with cyclists. Bred as hunting dogs, GSPs are sure-footed and have good reaction time, making them just as good—if not better—on trails as on the road.