Who needs to hit the gym when your dog can be your personal trainer?

People who own and walk dogs are 34 percent more likely to meet federal benchmarks for physical activity, according to a study led by Michigan State University that was published recently in the Journal of Physical Activity and Health.

The study indicated that people who walked their dogs walked about an hour longer per week than people who owned dogs but didn't walk them.

"We found people who walked their dog also had higher overall levels of both moderate and vigorous physical activities," said Mathew Reeves, an epidemiologist at Michigan State.

A study at the University of Missouri in 2009 found that senior citizens go for longer walks, and walk faster, when their companion is canine rather than human.

Dr. Charles Sturm, a family-medicine practitioner at West Penn Hospital, Forbes Regional Campus, in Monroeville, Pa., owned and walked a dog for 13 years.

"We walked 20 to 25 minutes in the morning and up to an hour in the evening," Sturm said. "Even longer on weekends."

"It's a very easy and convenient way to exercise," he said. "No special equipment is needed. You don't have to drive somewhere or go to a sports field to participate."

Dr. Dawn Marcus, a neurologist and pain researcher at the University of Pittsburgh Medical Center, has written a book, "Fit as Fido," which asserts that dogs can teach us a lot about healthy living.

"Dogs really are nature's personal trainers," Marcus told the Pittsburgh Post-Gazette. "They model fitness behaviors, and behaviors for eating and socializing, too."

Dogs are always eager to go for walks, she said. "Unlike your human exercise buddies, dogs are not going to beg off" if the weather is bad.

In addition to an eagerness to exercise regardless of weather, "dogs love sleep," Marcus said. "People who don't sleep are more likely to have diabetes, high blood pressure."

And when dogs are on their walks, they stop to socialize with other dogs, she said.

"Stopping and saying hello to other people is important to human health as well," Marcus said. "Research shows social interactions are essential to human health."

In addition to benefiting from following the example of dogs, we'd be healthier if we treated ourselves the way we treat our dogs, she said. Most dog owners feed their pets healthy food, and see to it that they don't overeat.

"The other thing we learn from our dogs is an attitude for approaching life," Marcus said. "The dog is always wagging his tail and is eager to go out."

The Michigan State study indicated that younger and older people are more likely than middle-aged people to walk their dogs, and that larger-breed dogs are taken for longer walks than are smaller dogs.