Which path is best for a walk — a paved surface or a dirt trail through the woods — depends on a variety of factors -- whether you're walking primarily for exercise, if you're trying to squeeze a walk in over your 30-minute lunch break or if you're concerned about getting injured. Maybe you’re more interested in taking a walk to clear your head and take a little mental escape. All of these factors come in to play. Thus, the question may not be which path is better, but which better suits your needs.
A Good Workout
You’ll likely walk faster on a paved surface, and the faster you walk the more calories you burn, right? After all, the American Council on Exercise's fitness calculator tells you that a 150-pound person who walks 2 mph burns 136 calories, while the same person who covers 4 miles in the same time burns 340 calories. Yet, “The Complete Guide to Walking for Health, Weight Loss, and Fitness” says you can burn up to 40 percent more calories exercising on a rough, uneven surface than on a smooth surface. Advantage: both are good for a workout.
Work More Muscles
While both surfaces can offer a good aerobic workout, walking on a rough surface may give you a better overall workout. When walking on a smooth surface, your stride varies less and the motion becomes more repetitive. Your body adapts to that repetition and performs more efficiently. And, sadly, that means you’re burning fewer calories, a real bummer if you’re walking to lose weight. It’s the same rationale behind CrossFit and other boot camp-type exercise programs that claim never to do the same workout twice -- keep your muscles guessing and you'll get a better workout. Advantage: dirt path.
People who stick to natural surface trails say they do so to avoid injuries from those repetitive motions that stress muscle, bone and joints. Likewise, people who stick to concrete sidewalks and greenways claim to do it for the same reason: Fewer chances to twist an ankle or take a spill courtesy of a tree root or rock. Curiously, there’s been no conclusive research into which surface is easier on your body. If you have balance and stability issues, you may be better off sticking to the sidewalk. If joint pain and shin splints are recurring problems, the dirt path may be more attractive. Advantage: assess your personal situation and decide.
Mental and Aesthetic Escape
Maybe you’re just as interested in the aesthetics as the athletics. Aesthetics are personal and subjective. Some find a walk along a babbling creek through a heavily wooded forest the ultimate escape. To others, the chaos of the natural world is nerve-wracking and the prospects of a wildlife encounter unnerving. Perhaps a walk along a manicured greenway, or a sidewalk winding through a landscaped office campus is just what you need to settle your nerves. Advantage: depends on what you find relaxing.
While you’d like to not have to think about it, but every time you head out for a walk you leave yourself vulnerable, to a degree. Generally, dirt paths tend to explore more remote, isolated areas. You’re likely to see fewer people; by the same token, you’ll have fewer people to call on if you need help. Paved surfaces, on the other hand, are more likely to wind their way through civilization: a sidewalk through your neighborhood, a greenway through open space to your favorite park. If trouble arises, you’re more likely to have help nearby. Advantage: sidewalks.
Joe Miller has been writing about health, fitness and outdoor adventure since 1992. For 10 years, he wrote a weekly outdoor adventure column, Take It Outside, for "The News & Observer" in Raleigh, N.C. He's the author of three books on hiking and backpacking, with a fourth, "Adventure Carolinas," scheduled for release from UNC Press in spring 2014. He has a Bachelor's degree in technical journalism from Colorado State University.