Simply taking a walk can be a powerful pill for mental, as well as physical health, say many authorities. When one considers the benefits, walking does make sense. After all, they allow us to view the beauty of nature, to encounter other members of the human race, to exert our dormant bodies, to strengthen muscles and organs such as the heart and lungs. This then brings more oxygen to the brain and body, as well as offering psychological benefits. When we step outside the home or office, we also step “outside” our problems, away from stressful relationships, and often find a new viewpoint on matters. A walk is almost a mini vacation — one which we can “afford” to take every day!
This may sound like a magic bullet, and in fact Dr. JoAnn Manson, Professor of Medicine at Harvard University, proposed that a daily stroll was “as close to a magic bullet as you’ll find in modern medicine. If there was a pill that could lower the risk of chronic disease like walking does, then people would be clamouring for it.”
Addiction and craving for cigarettes has even been improved by taking a 15-minute brisk walk, says Dr. Adrian Taylor, after a study was performed: “Relatively small doses of exercise should be recommended as an aid to managing cigarette cravings and withdrawal symptoms.” April edition of Addiction Journal, University of Illinois.
In Science News, Sept. 22, 2004) long-range benefits of walking are reported:

“Elderly men who are sedentary or walk less than a quarter of a mile per day are nearly twice as likely to develop dementia and Alzheimer’s disease compared to men who walk more than two miles per day, according to a study of over 2,200 Japanese-American men in Hawaii. The study is published in the Sept. 22 Issue of the Journal of the American Medical Association.”

And Mayo Clinic’s Dr. Joseph Levine reports that walking, rather than sitting, will improve both physical and mental health. After designing a treadmill “desk” to work at, Dr. Levine says, “I’ve become incredibly focused on completing things,” said Levine, who has banned chairs from his office. There are more benefits to the [treadmill] Workstation than losing weight. “…people want to escape from work because it is stressful,” Levine said. “…one of the key benefits to this approach to working is that it is de-stressing and depression prevention.”
We can conclude then, that at the end of the day, if one has taken a good walk and perhaps even a dose of Nature, they will be healthier and happier.