Kevin Moloney for The New York Times

If you’re looking for the latest in home exercise equipment, you may want to consider something with four legs and a wagging tail.

Several studies now show that dogs can be powerful motivators to get people moving. Not only are dog owners more likely to take regular walks, but new research shows that dog walkers are more active over all than people who don’t have dogs.

One study even found that older people are more likely to take regular walks if the walking companion is canine rather than human.

“You need to walk, and so does your dog,” said Rebecca A. Johnson, director of the human-animal interaction research center at the University of Missouri College of Veterinary Medicine. “It’s good for both ends of the leash.”

Just last week, researchers from Michigan State University reported that among dog owners who took their pets for regular walks, 60 percent met federal criteria for regular moderate or vigorous exercise. Nearly half of dog walkers exercised an average of 30 minutes a day at least five days a week. By comparison, only about a third of those without dogs got that much regular exercise.

The researchers tracked the exercise habits of 5,900 people in Michigan, including 2,170 who owned dogs. They found that about two-thirds of dog owners took their pets for regular walks, defined as lasting at least 10 minutes.

Unlike other studies of dog ownership and walking, this one also tracked other forms of exercise, seeking to answer what the lead author, Mathew Reeves, called an obvious question: whether dog walking “adds significantly to the amount of exercise you do, or is it simply that it replaces exercise you would have done otherwise?”

The answers were encouraging, said Dr. Reeves, an associate professor of epidemiology at Michigan State. The dog walkers had higher overall levels of both moderate and vigorous physical activity than the other subjects, and they were more likely to take part in other leisure-time physical activities like sports and gardening. On average, they exercised about 30 minutes a week more than people who didn’t have dogs.

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Dr. Reeves, who owns two Labrador mixes named Cadbury and Bella, said he was not surprised.

“There is exercise that gets done in this household that wouldn’t get done otherwise,” he said. “Our dogs demand that you take them out at 10 o’clock at night, when it’s the last thing you feel like doing. They’re not going to leave you alone until they get their walk in.”

But owning a dog didn’t guarantee physical activity. Some owners in the study did not walk their dogs, and they posted far less overall exercise than dog walkers or people who didn’t have a dog.

Dog walking was highest among the young and educated, with 18-to-24-year-old owners twice as likely to walk the dog as those over 65, and college graduates more than twice as likely as those with less education. Younger dogs were more likely to be walked than older dogs; and larger dogs (45 pounds or more) were taken for longer walks than smaller dogs.

The researchers asked owners who didn’t walk their pets to explain why. About 40 percent said their dogs ran free in a yard, so they didn’t need walks; 11 percent hired dog walkers.

Nine percent said they didn’t have time to walk their dogs, while another 9 percent said their dogs were too ill behaved to take on a walk. Age of the dog or dog owner also had an effect: 9 percent said the dog was too old to go for walks, while 8 percent said the owner was too old.

“There is still a lot more dog walking that could be done among dog owners,” Dr. Reeves said.

And the question remains whether owning a dog encourages regular activity or whether active, healthy people are simply more likely to acquire dogs as walking companions.

A 2008 study in Western Australia addressed the question when it followed 773 adults who didn’t have dogs. After a year, 92 people, or 12 percent of the group, had acquired a dog. Getting a dog increased average walking by about 30 minutes a week, compared with those who didn’t own dogs.

But on closer analysis, the new dog owners had been laggards before getting a dog, walking about 24 percent less than other people without dogs.

The researchers found that one of the motivations for getting a dog was a desire to get more exercise. Before getting a dog, the new dog owners had clocked about 89 minutes of weekly walking, but dog ownership boosted that number to 130 minutes a week.

A study of 41,500 California residents also looked at walking among dog and cat owners as well as those who didn’t have pets. Dog owners were about 60 percent more likely to walk for leisure than people who owned a cat or no pet at all. That translated to an extra 19 minutes a week of walking compared with people without dogs.

A study last year from the University of Missouri showed that for getting exercise, dogs are better walking companions than humans. In a 12-week study of 54 older adults at an assisted-living home, some people selected a friend or spouse as a walking companion, while others took a bus daily to a local animal shelter, where they were assigned a dog to walk.

To the surprise of the researchers, the dog walkers showed a much greater improvement in fitness. Walking speed among the dog walkers increased by 28 percent, compared with just 4 percent among the human walkers.

Dr. Johnson, the study’s lead author, said that human walkers often complained about the heat and talked each other out of exercise, but that people who were paired with dogs didn’t make those excuses.

“They help themselves by helping the dog,” said Dr. Johnson, co-author of the new book “Walk a Hound, Lose a Pound,” to be published in May by Purdue University Press. “If we’re committed to a dog, it enables us to commit to physical activity ourselves.”

A version of this article appeared in print on March 15, 2011 on page D6.