Doctor to patients: Take a hike

"I have a StairMaster right in my own basement, but honestly it's been there for years gathering dust and making me feel guilty," said Miriam, one of my patients. "It wasn't until I started walking the three-mile trail in the park near my house that I got serious about exercising. I do it now rain or shine. I love the fresh air. The best part is that I get a great workout and don't even mind sweating."

At this point, I have heard enough variations on Miriam's story that I have started to make formal "park prescriptions."

The prescribing instructions are considerably more detailed than ones you might get with a medication; they include the location of a local green space, the name of a specific trail and, when possible, exact mileage.

It turns out I am not alone. I've begun hearing about doctors around the country who are medicating their patients with nature in order to prevent (or treat) health problems ranging from heart disease to attention deficit disorder.

Eleanor Kennedy, a cardiologist in Little Rock, helped create a downtown "Medical Mile" with the support of local funders and the National Park Service's Rivers, Trails, and Conservation Assistance Program.

"If my patients feel that they can get outdoors, they are more likely to be consistent about exercise," she told me. "Whether you are waddling, walking or running, going out and exercising will help build your confidence, flexibility and adaptability."

Other physicians, from New Hampshire to Texas, are sending their patients out to wade through streams and walk on beaches and trails. Earlier this year the city of Santa Fe, N.M., launched a Prescription Trails program to target the high rates of diabetes in the community. The program, partially funded by the Centers for Disease Control and Prevention, includes a trail guide that physicians can hand to their patients.

"Of course, this is not the only answer to the obesity epidemic," said Michael Suk, an orthopedic surgeon and former health adviser to the NPS, "but it sure is a good start. All these insurance companies focus on prevention, but no one thinks of the free public land resources that we have at our disposal."

Richard Louv, author of the best-selling book "The Last Child in the Woods" and coiner of the term "nature deficit disorder," is all for these prescribing patterns. "I think that physicians can do more (to get people out into nature) than any other professional," he said. Louv's book and Web site (www.childrenandnature.org) cite dozens of studies documenting the positive impact that wilderness outings can have on mental and physical health. The fact that the American Academy of Pediatrics has invited Louv to deliver the keynote address at its 2010 annual meeting indicates that the larger medical community is starting to recognize the therapeutic value of time spent in the woods.

Fortunately, the custodians of nature are also on board. Howard Levitt, chief of interpretation and education at Golden Gate National Recreation Area, an NPS site in California, loves the idea of park prescriptions. In the near future, he and his colleagues hope to create a prescription "tool kit" for doctors, possibly in partnership with a large health organization such as Kaiser Permanente. "I see this as a mutually beneficial arrangement," Levitt said. "We know what parks exist to do and ... doctors want to care for their patients."

Rick Potts, the Park Service's chief of conservation and outdoor programs, echoed Levitt's enthusiasm: "Science is validating what moms have known for generations: Being outside is good for your health.

"I've never known a ranch kid on Ritalin," added Potts, who comes from rural Montana.

He expects support from the newly confirmed NPS director, Jonathan Jarvis. "We all see that the role of national parks in the 21st century is evolving. They are becoming more critical to our well-being as a society." As Potts continued talking, using such terms as "affordable prevention services" and "increasing access," he sounded more like a government official discussing health reform than one explaining park systems.

In fact, it's not too much of a stretch to think of our national park system as an integral part of our health care system; the NPS is already offering wellness services that are free and accessible to all, regardless of preexisting conditions. And according to Suk, the NPS wants to expand that access by supporting public open space developments such as Little Rock's Medical Mile in communities around the country.

So don't be surprised if, at your next visit to the doctor, you are handed a trail map and itinerary along with your lab slip.

So don't be surprised if, at your next visit to the doctor, you are handed a trail map and itinerary along with your lab slip. In fact, if you are not offered one, you should demand it.

And once you set foot on the trail, how hard should you exercise? I like what Dr. Kennedy tells her patients: "Hard enough that you can still talk in sentences but not in paragraphs."

• Miller is a family physician and an associate clinical professor at the University of California at San Francisco.