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Walking: Your steps to health

AUG 2009

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Every parent knows that a child's first step is a landmark event. It takes many months for that halting step to develop into a sturdy gait, but as toddlers become walkers, they open the door to independence, exploration, and, eventually, productivity. And just as walking is a signal achievement for each person, the two-footed upright gait is a banner accomplishment for our species. In fact, walking is one of the things that distinguishes man from all other animals.

Walking is an automatic, intrinsic human function, and it serves many practical roles. Strange as it seems, though, modern man appears determined to walk as little as possible. Not many men would walk five miles to work — but remarkably few choose to walk even a half mile to a friend's house or neighborhood store. And it's not just a question of walking for transportation; moving walkways whisk us through airports, and elevators and escalators lure many able-bodied men away from stairways. If the Segway "walking" machine ever catches on, walking will suffer yet another setback.

Walking doesn't get the respect it deserves, either for its health benefits, its value for transportation, or its role in recreation.

"But it's not aerobic"

Ever since the 1970s, the aerobic doctrine has dominated the discussion of exercise and health. In a scientific update of your high school coach's slogan "no pain, no gain," the doctrine holds that the benefits of exercise depend on working hard enough to boost your heart rate to 70% to 85% of its maximum, sustaining that effort continuously for 20 to 60 minutes, and repeating the workout at least three times a week.

Aerobic exercise training is indeed the best way to score well on a treadmill test that measures aerobic capacity. It is excellent preparation for athletic competition. And it's great for health. But intense workouts carry a risk for injury, and aerobic exercise is hard work. Although the aerobic doctrine inspired the few, it discouraged the many.

Running is the poster boy for aerobic exercise. With some preparation and a few precautions, it really is splendid for fitness and health. But it's not the only way to exercise for health. Perhaps because they've seen so many hard-breathing, sweat-drenched runners counting their pulse rates, ordinary guys often assume that less intense exercise is a waste of time. In fact, though, moderate exercise is excellent for health — and walking is the poster boy for moderate exercise.

Exercise guidelines

The benefits of physical activity depend on three elements: the intensity, duration, and frequency of exercise.

Because walking is less intensive than running, you have to walk for longer periods, get out more often, or both to match the benefits of running. As a rough guide, the current American Heart Association/American College of Sports Medicine standards call for able-bodied adults to do moderate-intensity exercise (such as brisk walking) for at least 30 minutes on five days each week or intense aerobic exercise (such as running) for at least 20 minutes three days each week. That makes running seem much more time-efficient — but if you factor in the extra warm-ups, cool-downs, and changes of clothing and shoes that runners need, the time differences narrow considerably. Add the time it takes to rehab from running injuries, and walking looks pretty good.

Mix and match to suit your health, abilities, personal preferences, and daily schedules. Walk, jog, bike, swim, garden, golf, dance, or whatever, as long as you keep moving. Remember that Einstein himself explained, "Life is like riding a bicycle. To keep your balance, you must keep moving."

Walking to health

Hundreds of medical studies show that regular exercise is good for health — very good, in fact. But many of these studies lump various forms of exercise together to investigate how the total amount of physical activity influences health. It's important research, but it doesn't necessarily prove that walking, in and of itself, is beneficial.

More than 2,400 years ago, Hippocrates said, "Walking is a man's best medicine." To find out if he was right, two scientists from University College London performed a meta-analysis of research published between 1970 and 2007 in peer-reviewed English-language journals. After sifting through 4,295 articles, they identified 18 studies that met their high standards for quality. In all, these studies evaluated 459,833 participants who were free of cardiovascular disease when the investigations began. Each of the studies collected information about the participants' walking habits along with information about cardiovascular risk factors, including — in most studies — age, smoking, and alcohol use and, in many cases, additional health data as well. The participants were tracked for an average of 11.3 years, during which cardiovascular events (angina, heart attack, heart failure, coronary artery bypass surgery, angioplasty, and stroke) and deaths were recorded.

The meta-analysis makes a strong case for walking. In all, walking reduced the risk of cardiovascular events by 31%, and it cut the risk of dying during the study period by 32%. These benefits were equally robust in men and women. Protection was evident even at distances of just 5½ miles per week and at a pace as casual as about 2 miles per hour. The people who walked longer distances, walked at a faster pace, or both enjoyed the greatest protection.

This meta-analysis included studies from seven countries on three continents. At the risk of being chauvinistic, here is a brief summary of three Harvard studies of walking and cardiovascular health:

  • Among 10,269 male graduates of Harvard College, walking at least nine miles a week was linked to a 22% lower death rate.

  • Among 44,452 male health professionals, walking at least 30 minutes a day was linked to an 18% lower risk of coronary artery disease.

  • Among 72,488 female nurses, walking at least three hours a week was linked to a 35% lower risk of heart attack and cardiac death and a 34% lower risk of stroke.

Extra steps

All 18 studies in this 2008 British meta-analysis are observational studies. As such, each investigation began with a defined group of healthy volunteers (called a cohort) and then observed them over a time period that averaged 11.3 years to see if people who walked enjoyed a reduced risk of cardiovascular disease and a lower rate of death. The results all provide a strong recommendation for walking; however, observational studies are less conclusive than randomized clinical trials. But one clinical trial of walking adds extra weight to the other research. A 10-year study of 229 postmenopausal women randomly assigned the volunteers to walk at least one mile a day or to continue normal activities. At the end of the trial, the walkers enjoyed an 82% lower risk of heart disease.

All 459,833 participants covered by the meta-analysis were free of cardiovascular disease when they enrolled in the 18 studies. But can walking help people who already have heart disease? Randomized clinical trials of cardiac rehabilitation say the answer is yes. A meta-analysis of 48 trials in 8,946 patients showed that moderate exercise — typically walking or riding a stationary bicycle for 30 minutes three times a week — produced a 26% reduction in the risk of death from heart disease and a 20% reduction in the overall death rate.

How walking works

The cardiovascular benefits of walking are biologically plausible; like other forms of regular moderate exercise, walking improves cardiac risk factors such as cholesterol, blood pressure, diabetes, obesity, vascular stiffness and inflammation, and mental stress. And if cardiac protection and a lower death rate are not enough to get you moving, consider that walking and other moderate exercise programs also help protect against dementia, peripheral artery disease, obesity, diabetes, depression, colon cancer, and even erectile dysfunction.

Ready, set, walk.

Walking vs. running

Walking is not simply slow running; competitive racewalkers can zip by recreational joggers. The difference between the two is not based on pace. At any speed, walkers have one foot on the ground at all times, but runners are entirely airborne during some part of every stride. As the pace increases, the percentage of each stride that is airborne increases; competitive runners have "hang times" of about 45%.

What goes up must come down. That's why running is a high-impact activity. Each time they land, runners subject their bodies to a stress equal to about three times their body weight. In just one mile, a typical runner's legs will have to absorb more than 100 tons of impact force. It's a testament to the human body that running can be safe and enjoyable. At the same time, though, it's a testament to the force of gravity that walkers have a much lower (1% to 5%) risk of exercise-related injuries than runners (20% to 70%).

illustration of human walk cycle

Walkers have one foot on the ground at all times.

Walking for life

Make walking part of your daily life. Walk to work and to the store. If it's too far, try walking to the train instead of driving there, and then get off the bus or subway a few stops before your destination. Instead of competing for the closest parking space or paying extra for a nearby lot, park farther away and walk to your destination. Go for a walk at lunchtime instead of spending all your time in the cafeteria.

You don't need any special equipment to walk in the course of your daily life. Supportive street shoes will suffice, but if you prefer, you can change into walking shoes for your commute or lunchtime stroll. And since you don't need to push yourself enough to sweat, you don't need special clothing; just stay warm in the winter, cool in the summer, and dry in the rain. But when the weather is really harsh or the streets slippery, put safety first and walk down long hallways, in a mall, or on the stairs (see box).

Climbing to health

Walking on streets and trails is superb for health. And so is walking up stairs. Coaches, cardiologists, and housewives have long been in on the secret of stairs. Many football coaches "ask" their players to charge up flight after flight of stadium steps to get in shape, and other competitive athletes put gymnasium stairwells to similar use. In the days before stress testing held sway, doctors would often walk up stairs with their patients to check out cardiopulmonary function. Even today, cardiologists tell heart patients they are fit enough to have sex if they can walk up two or three flights comfortably, and surgeons may clear patients for lung operations if they can manage five or six flights. As for housewives, taking care of a two- or three-story home is one reason American women outlive their husbands by an average of more than five years.

What's so special about stairs? Researchers in Canada answered the question by monitoring 17 healthy male volunteers with an average age of 64 while they walked, lifted weights, or climbed stairs. Stair climbing was the most demanding. It was twice as taxing as brisk walking on the level and 50% harder than walking up a steep incline or lifting weights. And peak exertion was attained much faster climbing stairs than walking, which is why nearly everyone huffs and puffs going upstairs, at least until the "second wind" kicks in after a few flights.

Because stairs are so taxing, only the very young at heart should attempt to charge up long flights. But at a slow, steady pace, stairs can be a health plus for the rest of us. Begin modestly with a flight or two, and then add more as you improve. Take the stairs whenever you can; if you have a long way to go, walk part way, and then switch to an elevator. Use the railing for balance and security (especially going down), and don't try the stairs after a heavy meal or if you feel unwell.

Even at a slow pace, you'll burn calories two to three times faster climbing stairs than walking briskly on the level. The Harvard Alumni Study found that men who average at least eight flights a day enjoy a 33% lower mortality rate than men who are sedentary — and that's even better than the 22% lower death rate men earned by walking 1.3 miles a day.

Does walking for transportation pay off? And how! A study of 12,000 adults found that people who live in cities have a lower risk of being overweight and obese than people who live in the suburbs. In Atlanta, for example, 45% of suburban men were overweight and 23% were obese; among urbanites, however, only 37% were overweight and 13% obese. The explanation: driving vs. walking. To stay well, walk for 30 to 45 minutes nearly every day. Do it all at once or in chunks as short as five to 10 minutes. Aim for a brisk pace of three to four miles an hour, but remember that you'll get plenty of benefit from strolling at a slower pace as long as you stick with it.

If you want to set more precise goals, aim for two to four miles a day. As a rule of thumb, urban walkers can count 12 average city blocks as one mile. Another way to keep track of your distance is to buckle a pedometer to your belt. Some just keep track of your steps, while others have bells and whistles such as timers, clocks, alarms, and bells — or at least chimes that ring out little tunes. You can get a decent pedometer for under $40. Even the best models can sometimes mistake a jiggle for a step, but a pedometer can help you keep track and can motivate you to take extra steps whenever you can. If you have an average stride length, count 2,000 steps as about a mile of walking. And if you're counting steps, you can use another rule of thumb to estimate your intensity: 80 steps a minute indicates a leisurely pace; 100 steps a minute, a moderate to brisk pace; and 120 steps a minute, a fast pace. Even without counting, you'll do well simply by reminding yourself to walk briskly. It's the only direction that researchers gave to a group of 84 overweight, sedentary volunteers, yet even without athletic experience, all of them achieved heart rates in the moderate 58% to 70% of maximum range.

In this high-tech era, technologically inspired workouts are the rage. For example, when George W. Bush took over the White House, he installed a treadmill on Air Force One. Like his father, Mr. Bush is athletic, fit, and dedicated to exercise and sports. Politics notwithstanding, both Presidents Bush set fine examples of exercise for maximum fitness. But remember that President Harry S. Truman's daily "constitutionals" set a democratic example of plain vanilla walking for health and pleasure (to say nothing of votes) in the course of daily life.

Walking for transportation is a good way to start any exercise program, and it's an excellent way to protect your health. Still, many men will get extra benefit from setting aside dedicated time to walk for exercise, health, and pleasure.

Genetic or kinetic?

The meta-analysis of 18 walking studies did not address a question that has bedeviled most studies of exercise and health: is the exercise itself protective, or do genetically healthier people simply tend to exercise more? But another important European study sheds light on the issue.

To learn if the effects of exercise depend on genetics and early family life, doctors in Finland studied nearly 16,000 same-sex twins. The participants were all healthy when the study began in 1975. All the volunteers provided information on their exercise habits and other known predictors of mortality. People who reported exercising for more than 30 minutes at least six times a month at an intensity corresponding to brisk walking were classified as conditioning exercisers, subjects who exercised less were considered occasional exercisers, and those who did not exercise were considered sedentary.

During the study's 20-year follow-up, 1,253 participants died. Even after accounting for other risk factors, exercise proved strongly protective, reducing the death rate of conditioning exercisers by 43% and occasional exercisers by 29%. But was the protection genetic or kinetic? Even among genetically similar twins, exercise was a strong independent predictor of survival. Twins who exercised regularly were 56% less likely to die during the study period than their sedentary siblings, and even twins who exercised only occasionally had a 34% lower death rate than their sedentary sibs.

Your shoes may have more to say about your health than your genes.

Walking for walking

Whether you walk in a business suit or a sweat suit, on city streets or country roads, it's still the same left, right, left for health. In fact, it's not a question of either/or, since every walk you take is a step toward good health.

Walking for walking's sake shows you are giving exercise the priority it deserves. It will get you away from the demanding routines of daily life, a nice plus for mental health. And by changing into walking shoes and athletic togs, you'll be able to build up to a pace that's difficult to achieve on the way to work.

Good shoes are important. Most major athletic brands offer shoes especially designed for walking. Fit and comfort are more important than style; your shoes should feel supportive but not snug or constricting. Look for a padded tongue and heel pad. The uppers should be light, breathable, and flexible, the insole moisture-resistant, and the sole shock-absorbent. The heel wedge should be raised, so the sole at the back of the shoe is two times thicker than at the front. Finally, the toe box should be roomy, even when you're wearing athletic socks.

Your shoes are worth a little thought, but your clothing is strictly a matter of common sense and personal preference. A T-shirt and shorts are fine in warm weather. An ordinary sweat suit will do nicely when it's cool, but a nylon athletic suit may be more comfortable. Add layers as the temperature drops; gloves and a hat are particularly important. If you really get into it, a water-repellent suit of Gore-Tex or a similar synthetic fabric will keep you warm without getting soggy with sweat.

For safety's sake, pick brightly colored outer garments, and always wear a reflector on country roads if it's dark. Walk facing cars if you don't have a sidewalk underfoot, and avoid high-speed and congested traffic. Beware of dogs and, for that matter, people; be sure unfamiliar locations are safe, and even then, try to walk with a companion.

Before you take a serious walk, stretch to warm up; stretch again to cool down afterwards. Start out at a slow pace, and slow down toward the end of your walk as well. Begin with routes that are well within your range, and then extend your distances as you improve. The same is true of your pace; begin modestly, then pick up your speed as you get into shape. Intersperse a brisk clip with a less strenuous stride, and then gradually extend these speedier intervals. Add hills for variety and additional intensity.

One of the nice things about walking is that you don't need special skill, much less lessons. The main thing is to walk naturally and comfortably. But if you want to aim for an ideal stride, a few tips may help. Try to keep your posture erect with your chin up, your eyes forward, and your shoulders square. Keep your back straight, belly flat, and butt tucked in. Keep your arms close to your torso, bent at the elbow. Take a natural stride, but try to lengthen your stride as you improve. Land on your heels, and then roll forward to push off with your toes. Swing your arms with each stride, and keep up a steady, rhythmic cadence.

To stay motivated, walk with a friend or listen to a radio or MP3 player. And for some people, the best motivation is a dog — studies show that owning pets is good for health, and walking the dog is a major reason for this benefit.

To avoid problems, back off if you are ill or injured, always listen to your body, stay well-hydrated, and avoid hazardous conditions. Consider walking in a mall if it's too hot, cold, wet, or slippery outdoors. You can also consider using a treadmill at home or at a health club.

Walking it off

Exercise burns calories. In the case of walking and running, the calories you burn depend much more on the distance you cover and your body weight than on your pace. This table shows calories burned per mile of walking or jogging on the level for people of varying weights:

A hundred or so calories a mile might not seem like much, but they can add up to better weight control. For example, a 2009 study of 4,995 men and women found that the average American gains about 2.2 pounds a year during middle age. But during the 15-year study, people who walked gained significantly less weight than those who didn't; the more walking, the less weight gain. And the benefit was greatest in the heaviest individuals. For example, walking for just 35 minutes a day saved a 160-pound person about 18 pounds of flab over 15 years of aging.

Your weight

Approximate calories per mile

120 lbs

85

140 lbs

95

160 lbs

105

180 lbs

115

200 lbs

125

220 lbs

135

Walking the walk

Walking has it all. Simple and natural, it doesn't require any instruction or skill. It can be a very modest form of exercise or it can demand enough skill and intensity to be an Olympic sport. You can walk alone for solitude or with friends for companionship. You can walk indoors on a treadmill or outside in the city or country, at home or away. You can get all the benefits of moderate exercise with a very low risk of injury. And to boot, walking is inexpensive. All things considered, Charles Dickens got it right: "Walk to be healthy, walk to be happy."