Erin Coburn and her buddy, Stihl, have had countless adventures in the past two years.
They've been hiking at Silver Star Mountain and played in the snow. They've taken trips to the beach and splashed in the ocean. They've gone horseback riding and snowshoeing. They've been boating and tubing on the Columbia River.
But nothing compares to tossing the Frisbee.
"He gets so excited," Coburn said. "I swear you can see the excitement in his eyes."
"He is one adventuresome dog," she added.
In June 2010, Coburn had major reconstructive surgery on her knee. For three months after the surgery, walking required a straight leg brace. She was having trouble finding motivation to exercise, so she asked her mom for a dog for Christmas.
That December, she got Stihl (pronounced steel), a 4-month-old mini Australian shepherd.
Slowly, Coburn and Stihl started exercising. Coburn hobbled as she tried to jog and Stihl trotted alongside her. Then they started hiking, beginning with the easier trails at Battle Ground Lake State Park.
"He needed to get out and walk, and I needed to get out and rehab," Coburn, 24, said.
The duo ventured on tougher and longer hikes, including a trek through Mount Hood National Forest to cut down a Christmas tree last winter, and tried new things, like inner-tubing. Stihl sat on Coburn's lap as their pair was towed behind a boat on the Columbia River.
"He likes the wind in his face and his ears," Coburn said. "He enjoyed it."
In fact, Stihl enjoys just about any outdoor activity, except for shooting, she said.
While Coburn has always been active, some of the exercising she does is strictly for Stihl's benefit. On a recent beach trip, Coburn was ready to head home. Stihl, however, had some energy to burn. So they spent 30 minutes walking on the beach, playing with the Frisbee.
"I wouldn't have stopped on the beach to walk for 30 minutes if not for him," said Coburn, who lives in Vancouver.
Research indicates Coburn isn't alone. Studies have shown that people who exercise with their pets are more active than those who don't have four-legged workout buddies.
Researchers at Michigan State University found that among dog owners who walked their dogs, 61 percent met federal physical activity recommendations (150 minutes of moderate activity per week).
Of those who don't have dogs, or have dogs but don't walk them, only about 46 percent met the same physical activity benchmarks, according to the research.
The researchers also found that people who walked their dogs were more likely to participate in other forms of physical activity and, on average, exercised 30 minutes more per week than the other groups.
Another study at the University of Missouri found that seniors who walked with dogs rather than human companions had greater physical fitness improvement. Those who walked with dogs increased their walking speed by 28 percent compared to just 4 percent for those with human walking partners, according to the research.
Vancouver resident Joanie Delzer regularly takes her guide dog, Jeanie, on 3-mile walks through town. Delzer, who is blind, said she wouldn't feel comfortable going on long treks without Jeanie by her side.
"I wouldn't go as many places. I wouldn't do as many things," the 61-year-old said. "I wouldn't go as far. I wouldn't be as motivated."
Jeanie, a rambunctious 2-year-old yellow Lab, benefits from the exercise, too, Delzer said. Eventually, Delzer hopes the pair can get up to 4- or 5-mile walks.
"I like to get out and do it," she said. "It makes me feel alert and alive. And it's good for my guide dog."
Coburn has future adventures in mind for her and Stihl as well. Coburn and her boyfriend went kayaking recently. If not for the chilly temperature, and water, Coburn said she would have loaded Stihl up on the kayak.
"We'll do just about everything," she said. "He's my buddy that I can do anything with."