Exercise partner.Here, as in so many other ways, humans and canines are ideally matched: Dogs need to be physically active. You need to be physically active.

Studies have shown people are more likely to adhere to an exercise program if they have someone to do it with. The advantages when that “someone” is a dog are great - chief among them, reliability. Your dog isn’t likely to miss your scheduled walk because he had to work late, has to drop the kids off at school or is hung over from the office holiday party.

“I think walking with your dog is an excellent way to exercise,” says Dr. Larry Golding, director of the exercise physiology laboratory at the University of Nevada, Las Vegas. “You can’t always find someone to walk with, but your dog will go anytime. They’ll never cancel on you.” A dog also provides a little extra security, especially for women who might like to walk outdoors before work or in the evening, but would be reluctant to do so alone.

Small wonder then that when exercise scientist Steve Blair of the University of South Carolina, author of the U.S. surgeon general’s fitness guidelines, offers tips on how to get active on a regular basis, one of his favorites is: “Walk the dog … even if you don’t own one.”

Walk off the weight

A study, published in the October issue of the journal Obesity, found that obese individuals who walked regularly with their dogs had weight loss rates of about 5 percent over the course of a year (their dogs lost weight, as well.)

“Companion dogs can serve as a social support system,” the researchers wrote, recommending pet owners “should make the most of their dog in an exercise and weight loss program.”

Barbara Navetta has been doing just that for 15 years. She had started a walking program years earlier, by pushing her children around in a stroller. When the kids got older, Navetta started taking the family dog instead, and these days she can be found walking the roads near her home in East Setauket with her greater Swiss mountain dogs, Striker and Xylo (pronounced like “xylophone”). Because Striker is 130 pounds and Xylo weighs in at 150, she has to walk them separately. The result is a briskly paced, four- to six-mile walk for Navetta, with a quick stop at home halfway through to change walking partners. She says the daily walks with the dogs provide a new dimension to her exercise. “They just enjoy being out,” she said. “The ‘Swissies’ were bred to pull wagons, and it gives them a sense of self-worth that they’re doing this.”

“Exercise is an extremely important part of a dog’s life,” says veterinarian Sheldon Rubin of Chicago, a spokesman for the American Veterinary Medical Association. “Unfortunately, a lot of dogs don’t get enough.”

Rubin says one of the most common problems he sees among dogs in his practice is obesity. “It has a lot to do with the way people want to show love to their dogs,” he says. “They think that food is the way to the dog’s heart.” A better option for the dog’s heart - not to mention your own - is to take your pet for a 30- minute walk five days a week. Before you do, Rubin recommends checking with your vet; some dogs may have arthritis or other conditions that might prevent or limit brisk walking.

One step at a time

While you can dictate the pace, Rubin says, keep in mind dogs need to build up distance gradually, just as humans do. “A dog will go any distance to please you,” he says. So watch for canine warning signs of overtraining: excessive panting, and any limping afterward.

Still, all dogs - even those with other health issues - can benefit from walking. When Sandra Sauer adopted Chloe from the Little Shelter in Huntington, her veterinarian told her to make sure she walked the dog regularly. An Australian cattle dog mix, Chloe had had cancer, but during her recovery was fattened up by well-meaning volunteers at the shelter. Since Sauer adopted her in June, Chloe has lost 4 pounds, a result of brisk 20-minute daily walks through the neighborhood in Mastic. An added benefit: “I wasn’t walking, so it forces me to have physical activity,” Sauer admits. “It’s been very good for me.”

Dog-walking has been good for Danny Frank of Levittown, as well. Frank, 32, adopted Mac, a Lab mix, and Taz, a German shepherd, from the North Shore Animal League in September 2005 and now walks them twice a day, for 30 to 45 minutes. “I have a gym membership that I pay monthly and that I rarely use,” Frank says. Walking with Mack and Taz, he says, “is the best way to keep me fit with my time constraints.”

Which is why, if you’re looking for ways to get you out the door and active this winter, look no further than that tail-wagging, eager-to please, four-legged friend.

He’s a walker, too.

The North Shore Animal League and Weight Watchers are holding an “Adopt a Walking Buddy” campaign to promote dog adoption and regular physical activity through the winter. For more information and tips on winter dog-walking, visit animal league.org/walking buddy.