Research has shown that it's easier to be physically active and stick with an exercise program when you team up with a workout buddy, Kushner said. But unlike human partners, who might make excuses for not wanting to go for a walk or run, a dog never will. They will generally be the first ones at the door, ready to go, rain or shine.

Finding the right walking speed to reap health benefits is easy, said Dr. Dawn Marcus, a professor in the anesthesiology department at the University of Pittsburgh Medical Center. "If you're so winded, you can't talk with someone, then you're probably walking at too hard of a pace," she said. "On the other hand, if you're walking so slowly that you can easily sing, you're probably not walking fast enough."

If your dog tends to saunter down the street, she said, you can intensify the workout by taking a hillier route or by stepping on and off curbs.