Read an Excerpt
The Healing Power of Exercise
Your Guide to Preventing and Treating Diabetes, Depression, Heart Disease, High Blood Pressure, Arthritis, and More
By Linn Goldberg Diane L. Elliot John Wiley & Sons
ISBN: 0-471-34800-7
Chapter One
Exercise: The Best Medicine If you were told you could have more energy, be healthier, and live longer by doing something that takes a little more than one minute out of every two hours, would you do it?
Do you have the time to exercise 90 to 120 minutes a week? Well, if you do, medical research indicates that you can accomplish a death-defying act. You will feel better, roll back your physiological clock, and gain more benefits than you would from any potion or medication ever invented. Participating in a program of regular physical exercise can accomplish the following:
Increase your life span
Reduce your chance of developing heart disease
Reduce your risk of stroke
Lower your risk of developing certain cancers
Prevent and treat high blood pressure
Prevent and treat diabetes
Burn fat and build muscle
Strengthen your bones
Improve cholesterol and triglyceride levels
Prevent and treat lower back problems
Reduce stress, anxiety, and symptoms of depression
Reduce your risk of developing glaucoma
Boost your energy level
Exercise: The Early Years
Our bodies are not much different today than they were 2 million years ago, when Homo erectus first walked on the planet. That is about the time when we began using stone tools, and the screwdriver and ginsu knives were just dreams. Homo sapiens appeared almost 500,000 years ago. These ancestors had a larger brain, began cooking their food, and over time developed jaws with smaller teeth. Today, our organs, basic physiology, and biological systems are identical to those of our ancestors who lived 40,000 years ago.
After years of research, the United States Public Health Service declared "physical fitness and exercise to be one of the... priority areas in which improvement is expected to lead to substantial reduction in premature morbidity and mortality." This is not an original conclusion. For example, John Dryden (1631-1700) wrote the following:
Better to hunt in fields for health unbought; Than fee the doctor for a nauseous draught. The wise, for cure, on exercise depend; God never made his work for man to mend.
Before this, the twelfth-century physician Moses Maimonides stated, "Anyone who sits around idle and takes no exercise will be subject to physical discomfort and failing strength."
We have rediscovered what has been known all along. Exercise improves health. Understanding why these healthy benefits occur requires a lesson in paleoanthropology, which is the study of what life was like for our ancient ancestors.
Cort the caveman hunted elk and fished the streams. He and his prehistoric tribe members journeyed for days at a time, hiking over open fields and harsh terrain. The women, including Corta, his cave-mate, gathered nuts and berries, covering between three and five miles of ground each day. When all the food was captured and gathered, those who had not been eaten by bears or crushed by woolly mammoths returned to their caves. Cort, Corta, and their tribe feasted and stocked the cave to prepare for winter, when little food could be gathered or hunted.
Our primitive forebears were survivors whose bodies thrived on physical activity. Hunting game and gathering nuts, seeds, and fruits were performed by groups, or clans, of 25 to 50 people. Over thousands of centuries, the human body adapted to this highly energetic lifestyle. Our cardiovascular system, endocrine glands, muscles, and bones still function best when the body is challenged by regular bouts of exertion. Makes sense, doesn't it?
While many of us are glad we don't have to run after wild game with a handmade spear and are happy with our modern conveniences such as supermarkets, current lifestyles do not provide us with the amount of exercise our bodies need. Channel surfing, jumping to conclusions, putting your shoulder to the grindstone, and leaps of faith just are not enough for optimum health!
Modern Lifestyles
Most modern jobs never challenge most of our 600 muscles. Industrialization has advanced so quickly that our bodies have not had the time to adapt to the changes. We still live with the same ancient anatomy, organs, and biochemical profile that Corta and Cort had. So, it is not surprising that there has been an epidemic of cardiovascular and degenerative diseases. Use of automobiles, information superhighways, and drive-through windows has come at a price.
It is easy to slip into a sedentary lifestyle. Because of our highly mechanized society, we hardly notice how out of shape we really are. It's only when the elevator is not working and you need to climb five flights, there is yardwork to do, or you go one-on-one in a basketball game with a 12-year-old that you might realize your real physical condition. When you play that basketball game, you might score a few quick buckets, but then your legs begin to feel like rubber and breathing becomes labored. Your chest starts to hurt with each breath. You know that the only way to avoid being totally embarrassed by your young adversary is to play smart. Only your age and experience help you to last the entire game. For most of us, however, such reminders of being out of shape are rare. It is easy to avoid climbing stairs, and you can watch your children's basketball and soccer games rather than participate. So it's not surprising that with everything else going on in your life, getting into shape may not be a priority. But it should be.
Every minute of every day, about three Americans will have a heart attack. Cardiovascular diseases are the major cause of death in the United States for both men and women. In fact, more women than men die of heart disease-it just happens to them about 10 years later. Many times, there are no warning symptoms; for nearly half of all those who have heart disease, a heart attack is the first symptom.
Lack of exercise is one of the major risk factors for developing heart disease. Not exercising is similar in risk to having untreated high blood pressure or smoking a pack of cigarettes each day. Your body needs regular physical activity to stimulate the complex metabolic and hormone pathways that work best only when you exercise.
Making a Difference in Your Health
Imagine that you are going to your high school reunion. Think about your classmates who stayed in shape and compare them to the ones who gained the typical one to two pounds of weight each year after graduation. How many pounds of fat have they accumulated around their waist, hips, and thighs? What do you think this has done to their health?
Dr. Ralph Paffenbarger, a professor at Stanford University, has been studying Harvard alumni for several decades. Because Harvard University keeps meticulous track of its graduates, he was able to follow nearly 17,000 alumni for more than 15 years. After a rigorous investigation of their lifestyles and habits (both good and bad), he found that those men who exercised regularly lived longer!
He also found that it is never too late to start exercising to reduce your health risks. Harvard grads did not have to be college athletes to benefit. In fact, many alumni became active later in life. On the other hand, being a college athlete did not protect those students from developing medical problems if they did not remain active after graduating. It seems you can't just store up and "bank" the benefits of exercise. It is what you are doing now and continue to do in the future that is critical.
Your Job Can Make a Difference
Many studies that consider the workplace have led us to the conclusion that if you are active on the job, you increase your chances of avoiding narrowed arteries and can live a longer life. Examples of these studies are revealing. For instance, bus conductors in England who walk up and down stairs, taking tickets on those double-decker buses, have less heart disease than those who sit and drive. Similarly, letter carriers who walk on their route have less cardiovascular disease than postal clerks who sit at their desks. Dock workers who lift, pull, and push the cargo have fewer heart attacks than the longshoremen who check the cargo, using only a clipboard and pen.
Most of these research studies used questionnaires, rather than exercise tests, to measure physical activity. The problem is that it is often difficult to compare different types of exercise. For instance, how does stacking boxes compare to housework? Is gardening similar to brisk walking? Although surveys are useful, they are not able to specify the "dose" of exercise, such as walking, jogging, cycling, or lifting weights, needed to improve your health.
What You Do in Your Spare Time Can Make a Difference
The Aerobics Institute, located in Dallas, helped answer the question, "How much exercise do I need?" At the Institute, people enroll in programs to begin and maintain regular physical activity. Those who join are examined by treadmill testing, which is a very accurate measure of physical work capacity. Those who join the programs are classified by their level of fitness. Scientists divided participants into five levels, from 1 (the most fit), to 5 (the least fit). Just as in the results of questionnaire studies, those who had greater fitness lived longer.
Researchers then examined the initial fitness level of the participants, how much exercise they did, and their overall health. What they found was that going from fifth place to fourth place had the greatest benefit (the most bang for the buck). Although higher degrees of fitness were related to an even longer life span, the largest improvement occurred with only small amounts of exercise.
What this means is that you don't need to run marathons or pump iron for hours to benefit from physical activity. You can improve your health and prevent disease by simply going for a 30-minute walk three to four times a week. So, exercising for less than 1 percent of the week will enable you to feel better and gain the advantages of less heart disease and a longer life.
How Does Physical Activity Prevent Disease?
Many researchers now believe that physical activity stimulates specific enzyme systems and hormones, which in turn reduce risk factors for disease. The changes include decreased clotting of our blood (similar to the effect of aspirin) to lower chances of a heart attack, improved blood fat (cholesterol and triglyceride) levels, better control of blood sugar and blood pressure, and creation of stronger bones, to name a few. With all these changes occuring, you reduce your chances of heart disease, diabetes and its potential kidney and eye disease, along with the complication of thinning bones (osteoporosis).
Regular physical activity improves your health in many ways. Specific benefits and recommendations are discussed in the following chapters. As an overview, Table 1.1 lists many of these health benefits. As physicians concerned with health and exercise, we have seen countless people feel better and gain health through regular physical activity. In this book we present their stories and how they did it.
Lowering Blood Pressure
Bill and Bob didn't exercise. They did not know each other when they enrolled in the university's research program to find out whether exercise could help lower their blood pressure. Both men were taking medication for hypertension (high blood pressure) and had desk jobs. Neither had participated in any regular physical activity for over 10 years.
Bill was 48 years old and wanted to start an exercise program because he thought he was too out of shape. Bob, at age 39, was motivated to be in the study because he had just recovered from back surgery for a herniated disk. Both men were overweight. Bill's body fat percentage was 22 percent, while Bob's body fat percentage was 29 percent. (The normal body fat percentage is between 12 percent and 18 percent for a man, and between 18 percent and 25 percent for a woman.)
Bill and Bob first met while riding exercycles during training sessions. They discussed family, friends, and their jobs during their workouts. So they could exercise together, they coordinated their work schedules and rode for four 30-minute sessions per week.
Before and after the 16-week study, Bill and Bob's fitness levels were measured on a stationary bike with oxygen uptake analysis. With these studies, we were able to pinpoint their exercise capacities. Their aerobic fitness levels (the ability to use oxygen during exercise) improved by more than 20 percent. In addition, after four months of regular exercise, Bill's body fat dropped to 17 percent, while Bob reduced his to 23 percent. Both Bill and Bob packed on more muscle mass as well. Bob's blood pressure normalized without medication. Although Bill still required medicine to lower his blood pressure, he needed only half of his previous dose.
Now, 10 years later, Bob and Bill meet five times a week to ride the exercycle and "treat" their hypertension with exercise.
Bill and Bob's adventure on the stationary bikes did not get them far, distance-wise. However, both felt younger, and their continued training has no doubt added years to their lives. Bob believes that his exercise-induced trimmer waistline reduced the strain on his back, too. His belief has been affirmed by medical research.
There are about 50 million adults in the United States with high blood pressure, and only half of these people know their blood pressure is elevated. Maintaining your fitness can protect you from developing hypertension. Dr. Steven Blair and colleagues observed the blood pressures and fitness levels of over 4,000 men in one study. During an 8 1/2-year period, they found a 52 percent increase in the number of men who developed hypertension among those who were less fit. Bill and Bob's experience illustrates how regular physical activity can actually treat high blood pressure.
Most medical studies show that you don't have to train hard to lower blood pressure. For example, walking for 30 minutes evey other day can reduce the systolic (the top number) blood pressure by about 11 points (millimeters of mercury, or mm Hg) and decrease diastolic (the lower number) blood pressure by 8 mm Hg. This is enough to reduce the risk of a stroke by more than 25 percent.
Losing Weight
Tom is 36 years old, happily married, and has three young children. He works as a regional representative for a large electronics firm. Tom was a high school athlete, but he participated in his last regular exercise program when he attended college. Now the extent of his regular physical activity is walking 50 or 100 feet from his car to his customer's business. His weight has slowly increased about one-quarter pound each month. Now he finds that his weight is 40 pounds above his weight 15 years ago.
Continues...
Excerpted from The Healing Power of Exercise by Linn Goldberg Diane L. Elliot Excerpted by permission.
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