The Washington Post - February 9, 1999

Throughout civilization, humans have struggled to create devices to ease our physical burdens. From the wheel to the pentium processor, labor-saving milestones have marked mankind's progress in freedom from back-breaking demands.

But now, health experts warn, our passion for avoiding physical activity has spiraled out of control. We've evolved a push-button, drive-through, remote-control mentality that has resulted in a weak, overweight society where an "epidemic of inactivity" is responsible for an estimated 250,000 deaths per year, according to a 1995 report published in the Journal of the American Medical Association.

Sedentary living and junk foot diets have combined to cause an alarming increase in obesity, even among children, many of whom are developing chronic illnesses--such as type 2 diabetes and high cholesterol--once seen only in adults. Inactivity-associated ailments, such as osteoporosis and high blood pressure, are also on the rise as the population ages. Nursing homes are filled with seniors who are institutionalized primarily because their under-used muscles and bones have left them incapacitated.

Despite the much-publicized fitness movement, fewer than one in four adults exercises regularly. The vast majority of Americans still spend the vast majority of their days on their increasingly vast butts. "Most people don't realize how little physical activity they actually get and how important it is for them to use every opportunity they have to be active," says Yale University obesity expert Kelly Brownell. "We live in an increasingly toxic food and physical activity environment."

Brownell points to greater use of moving walkways, automatic doors, commuters and other "conveniences" that make it less necessary-or possible-to move during the day. The resulting inactivity is a health hazard on par with smoking, high blood pressure and high cholesterol, say Brownell and other experts in the field.

Health vs. Fitness Benefits

One reason most people don't exercise is because they're confused about how to get fit. Fads and gimmicks promise impossible results and fitness trends change so that many people don't know what they're supposed to do to shape up.

In the '70s, running was touted as the ticket to fitness, and people were told exercise had to be vigorous and sustained or it didn't count. In the '80s, aerobics classes boomed, and exercisers were urged to go for the burn--while taking their pulse and figuring their target heart rate so they could workout at the proper intensity. In the early '90s, exercise machines exploded in popularity and it seemed essential to wear Lycra--or at least Spandex--and join a gym to shape up.

Today the message is much simpler. Research show that moderate activity can yield major health benefits. As a general recommendation, public health officials are promoting a basic fitness formula: Sit less, move more.

"Almost any activity that gets you up and moving around is probably better for you in some ways than continuing to sit," says Dallas epidemiologist Steven N. Blair, who served as senior scientific editor of the U.S. Surgeon General's 1996 Report on Physical Activity and Health. Designed to jump-start our sedentary society, the report summarized the scientific evidence of exercise's wide-ranging health benefits and offered this simple exercise prescription:

Burn 150 calories per day through physical activity such as a 30-minute walk, 15-minute run or 45 minutes of washing and waxing a car.

In other words, put back some of the physical energy expenditure that technology has removed from our lives. Americans expend about 800 fewer calories per day than our parents did (the equivalent of four glazed donuts), says Blair. He advises people to integrate move movement into their lives through simple practices like taking the stairs and parking in the furthest space. This like of "lifestyle activity" can provide health benefits similar to a traditional gym-based workout, according to a study published last month in the Journal of the American Medical Association. The conclusion: Every step you take counts.

While this user-friendly activity prescription--dubbed "exercise lite"--will confer health benefits, it may not be enough to provide fitness benefits to those with more ambitious physical goals. A major finding of the past 20 years from research on physical activity is this distinction between the health benefits and the fitness benefits of exercise.

The health benefits of moderate activity are substantial, notes the Surgeon General's report. They include a reduced risk of numerous chronic diseases--including coronary heart disease, type 2 diabetes, hypertension and colon cancer-and improved mental health and enhanced physical functioning. In addition, most sedentary people who add 30 minutes of moderate activity to their days will lose some body fat and experience improvements in blood pressure, blood glucose and blood cholesterol.

But this modest amount of exercise probably won't be enough to reshape your body or win you a gold medal in the local 10-K race. People with appearance or goals need to do more exercise than the 30 moderate minutes necessary for health effects.

Fitness benefits, such as increased muscle strength and improves in heart and lung capacity generally require doing a specific kind of activity at a certain intensity, frequency and duration. For example, achieving cardiorespiratory fitness requires doing aerobic exercise at a "somewhat hard" intensity (55 to 65 percent to 90 percent of maximum heart rate) for 20 to 60 minutes, three to five days a week.

"There is a dose response to exercise," notes the American College of Sports Medicine in its newly revised guidelines for adult fitness. "Many significant health benefits are achieved by going from a sedentary state to a minimal level of physical activity; programs involving higher intensities and/or greater frequency/durations provide additional benefits."

Design-It-Yourself Exercise Program

To achieve optimal fitness as well as health benefits, it's necessary to participate in a well-rounded program that includes these three forms of exercise:

• Cardiovascular (aerobic) activities that strengthen the heart and lungs and help control weight
• Resistance exercise that strengthens muscles and bones
• Stretching to maintain flexibility

And don't believe those television infomercials--there is no, single "best way" to get fit. There are countless exercise options, depending on your preferences, finances, abilities and location. The best exercise for you, say experts, is the one that you'll enjoy and will do regularly.

For example, those who like going to a health club (and can afford membership) can do a gym workout three times a week for an hour, doing 30 minutes on an aerobic machine, 15 to 20 minutes lifting weights and 5 to 10 minutes stretching. People who like fitness classes can enroll in a YMCA, recreation department or university-based program that meets three times a week for an hour and includes aerobic, strengthening and stretching exercises.

Or you can get fit by yourself--or with friends and family--at home. One of the most accessible ways is by taking a brisk, 30 minute walk, followed by five minutes of stretching, three days a week. Add 15 to 20 minutes of resistance exercises, two or three days a week, using dumbbells and ankle weights and you'll be doing all you need to get fit. If you'd rather not walk, you can dance, cycle, swim, skate, jump rope, run, climb stairs, cross country ski or do any other continuous activity that increases your breathing and the heart rate for 20 to 60 minutes.

In fact, one of the major trends in the fitness industry has been the explosion in exercise options-at home and in the gym. Nearly one-third of U.S. households own exercise equipment, according to a 1997 study, sponsored by the Fitness Products Council, an association of equipment manufacturers. Treadmills and free weights are among the most popular home devices.

At health clubs, you can now choose from a smorgasbord of aerobic alternatives ranging from group stationary cycling--where high-energy instructors lead a class of pedal pushers on a sweat-soaked imaginary journey--to group weight training classes and MTV dance inspired workouts.

There's also been a surge of interest in Eastern-influenced classes that focus on connecting the mind, body and spirit through the breath. These include yoga, tai chi, karate and qi gong. Boxing-style classes are hot with the twenty something set, who punch and kick their way through cardio-kickboxing workouts. In addition, outdoor activities have boomed in popularity--particularly those that can be done by the whole family, such as hiking and walking.

Yet despite the growing array of exercise options available, most people still won't do the amount--or the intensity--of physical activity required for fitness. Lack of time is the most commonly cited reason, followed by dislike of vigorous exercise and lack of access to facilities.

That's why public health professionals are campaigning to spread the word that simply adding a relatively small amount of moderate activity into your life will at least confer major health benefits.

A Pyramid Theme

A graphic illustration of this new approach to fitness is the Physical Activity Pyramid. Modeled after the Department of Agriculture's well-known Food Guide Pyramid, the Physical Activity Pyramid helps ordinary people "understand basic physical activity concepts," write Arizona State University professors Charles Corbin and Robert Pangrazi in the ACSM's Health and Fitness Journal.

The base of the pyramid--or level 1--represents lifestyle physical activity, the accumulated 30 minutes of moderate activity (such as raking leaves or walking) promoted by the U.S. Surgeon General's Report. Everyone should do at least this much activity to gain important health benefits.

People who want to achieve fitness benefits, such as getting stronger or doing well in sports, need to move "up" to level 2 of the pyramid, which consists of active aerobics and active sports such as aerobic dance, jogging, tennis and racquetball. Doing these more vigorous activities at least three days a week for at least 20 minutes at a time can significantly boost cardiovascular fitness. Men over age 40 and women over age 50 who have been sedentary--and people of any age with risk factors for heart disease-- should consult a physician before starting a program of vigorous activity.

Moving up to level 3, which includes flexibility and muscle strengthening exercises, offers even more fitness benefits. Flexibility exercises should be done three to seven days a week, while muscle-strengthening exercises only need to be done two to three days a week.

At the top of the pyramid is inactivity. "Inactivity is not necessarily bad and is even advantageous when it's done in moderation," Corbin and Pangrazi note. "But long periods of inactivity (other than normal sleep) should be limited."

This is the bottom line message about exercise and health: Don't just sit there, move something.

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SIDEBAR: How Much Exercise is Enough?

How much exercise is enough?
The answer depends upon your goals. Here are some general guidelines for physical activity that will help you reach specific goals.

Health Benefits
Burn 150 calories per day through physical activity such as a 30-minute walk, 15-minute run or 30 to 45 minutes of gardening. Or, think of it this way: Accumulate 30 minutes of moderate activity each day.

Heart and Lung Fitness
Do an aerobic exercise (such as walking, cycling, running or swimming) three to five days a week, at about 60 to 90 percent of your maximum heart rate, for 20 to 60 minutes, either working continuously or by accumulating intermittent bouts of at least 10 minutes each. The higher intensity the exercise, the shorter the workout necessary to achieve the "training effect"--a complex constellation of physiological changes that occur as your body begins to adapt to the demands of aerobic conditioning. For example, a jog that gets your heart rate up to 140 beats per minute will give you a training effect in just 20 minutes, while a walk that gets your heart rate slightly over 110 beats per minute would take about 45 minutes to achieve the training effect.

To calculate your target heart rate or "training zone":

• Subtract your age from 220, this is your approximate maximum heart rate.
• Multiply this number by 0.6 to get your lower heart rate limit for aerobic exercise and by 0.9 to get your upper heart rate limit for aerobic exercise.

Example: If you are 40 years old, you'd subtract 40 from 220 and get 180. Then you'd multiply 180 by 0.6 to get your lower-limit heart rate, 108, and by 0.9 to get your upper-limit heart rate limit, 162. This means, when you exercise, your heart rate should stay in the range of 108 to 162 beats per minute.

Bone and Muscle Strength
Do resistance exercises (lifting weights or using a strength-training machine) two to three days a week. Do one set each of 8 to 10 exercises that strengthen the major muscle groups--arms, shoulders, chest, back, abdominals, hips and legs. Pick a weight heavy enough for you to lift at least eight, but no more than 12, times. (Older and more frail people--approximately 50 to 60 years old and above--may find it more appropriate to choose a lighter weight they can lift at least 10, but no more than 15, times.)

One set of each exercise is sufficient to boost strength and prevent loss of muscle mass in most adults, but three-set regimens may provide slightly greater benefits if time allows.

Flexibility
Do range-of-motion and flexibility exercises for all the major muscle groups a minimum of two to three days a week, by incorporating stretches into your overall fitness program. Stretch before and after aerobic activity, but be sure to warm up with some gentle activity before you stretch. Get in the habit of stretching tense muscles throughout the day, particularly after sitting or standing for an extended period of time. Don't bounce. Go to the point where you feel mild tension, then hold the stretch for 6 to 15 seconds while breathing naturally.

Weight Loss
Do exercise that burns about 300 to 500 calories a day, four to six days a week. (A 175-pound person burns about 360 calories during a brisk, one-hour walk.) Be sure to eat properly too, by controlling calorie intake and choosing appropriate portions of healthy, low-fat foods.