Uphill or down: The health benefits of hiking depend on where you’re
headed
Don’t ignore the descent — or the stairs down — as an exercise strategy.
Hiking is a popular way of being active outdoors, especially during summer. Although everyone knows that climbing up a hill or mountain is a great workout. We tend to see reaching the top as the end of the “real” exercise and the descent as easy street. But research from the Vorarlberg Institute in Feldkirch, Austria, suggests that heading downhill is a form of exercise with unique health benefits.
The hike up largely involves concentric (muscle-shortening) exercise — the kind that occurs. When you bend your arm to “make a muscle.” Hiking downhill is eccentric (muscle-lengthening) exercise. The result of the muscles’ braking action as they resist the pull of gravity on your body. (More generally, eccentric exercise occurs whenever you lower a weight against resistance.) The study, presented in November 2004 at an American Heart Association meeting in New Orleans, concluded that each of these exercise modes has distinct effects on blood sugar and blood fats.
Austrian researchers randomly divided 45 healthy volunteers who were not regular exercisers into two groups. Three to five times a week for two months, one group hiked up a ski resort mountain and came down by cable car, while the other group took a cable car up and hiked down. The uphill and downhill hikes involved a change in altitude of about 1,700 feet. After two months, the two groups switched exercise programs and repeated the experiment. Subjects were told not to change their eating patterns. At the start of the study and after each two-month exercise period, researchers measured the participants’ blood sugar, cholesterol, and ability to remove glucose and fat from the blood.
Both uphill and downhill walking reduced LDL (“bad”) cholesterol by about 10%. Only uphill hiking (concentric exercise) reduced triglyceride levels (triglycerides are an independent risk factor for heart problems). The surprise was that although downhill (eccentric) exercise did not lower triglycerides, it was almost twice as effective as uphill hiking at removing blood sugars and improving glucose tolerance.
These results may have implications for people. Who can’t engage in more strenuous types of cardiovascular exercise — for example, older people who’ve been sedentary and are just starting to exercise. Research by other groups has shown that walking on a downhill slope can enhance physical movement (that is, increase walking speed) without added cardiovascular or metabolic stress. Also, people with diabetes, who particularly benefit from a glucose-lowering workout, may find downhill walking more manageable than aerobic or climbing activities.
How practical is this kind of exercise on a day-to-day basis? Treadmills with downhill settings are expensive, and they’re uncommon outside sports medicine or rehabilitation centers. But you can step up your downward exercise more conveniently. Many ski areas offer chairlift or gondola rides to the top of the slope during the off-season. You might also try taking the stairway down instead of the elevator whenever you can.
Take it easy, though. Eccentric exercise is more likely than the concentric type to cause muscle soreness a day or two later. This delayed-onset soreness is thought to be an inflammatory response to exercise-induced muscle fiber damage. Fortunately, the effect lessens with subsequent exercise.
Protect your knees
Downhill exercise poses some risks. Compared to walking on a level surface, it places twice as much pressure, or load, on the knee joints. But you can take some simple precautions to improve your control and stability and reduce wear and tear on your knees. Walk slowly, take smaller steps, and place your feet carefully (don’t jump down) — landing heavily can irritate the knee joints and cause bursitis or mild arthritis. Don’t go straight down a slope; take a “zigzag” route, to keep the grade as gentle as possible. Make use of nearby trees and branches for support. You can also use hiking or trekking poles. Which reduce the load on both knee and hip joints while promoting a well-rounded workout by requiring you to use your arms. Ordinary ski poles will do, but hiking poles have extra features, such as collapsibility, angled grips, and sometimes shock-absorbing springs. Expect to spend around $100 if you decide to go this route. Well-fitted, supportive hiking boots also help protect your joints. Try on boots that are a half-size larger than you’d ordinarily wear. Make sure they have good ankle support, are snug at the heels, and provide plenty of room for the toes and extra sock layers. The inside should have adequate cushioning to absorb some of the impact as you hike downward. Some people use a knee brace or ACE bandage around the knee to help stabilize the kneecap and reduce the likelihood of inflammation and irritation. Downhill walking puts more stress on artificial joints than uphill walking. If you have an artificial knee or hip, consult your orthopedic surgeon before going on a mountain outing. Some experts advise hikers with artificial joints to avoid making descents altogether. At the very least, use trekking or ski poles and avoid wearing a backpack. |