Hundreds of studies show that regular exercise is good for health. But if you're not a runner or biker, or are only interested in-or capable of-less strenuous forms of exercise, can you still expect a health boost? You can, indeed, walk your way to better health, reports the August 2009 issue of Harvard Men's Health Watch.
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 stepsAll 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%).
Walkers have one foot on the ground at all times.
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