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Cardio-vascular Health
Exercise, Heart Rate
Why sould you exercise?
By Dr. W. Gifford Jones
Dr. Logan Clendening in his book "Modern Methods of Treatment" wrote in 1924, "faddists are continually proclaiming the value of exercise but four out of five people are more in need of rest." Mark Twain echoed this sentiment when he stated he had gone to the funerals of many friends who believed in more exercise than he did. But in 1873 the Earl of Derby during a speech in Liverpool remarked," Those who do not find time for exercise will have to find time for illness." Today controversy remains about the value of exercise. But if you ever get into a debate on this topic or wonder if working up the perspiration is worthwhile, here are several positive sound reasons for the exertion.
Exercise has a beneficial effect on the nervous system. Paul Dudley White, Harvard's renowned heart specialist, stressed,"If you want to know how flabby your brain is, feel your leg muscles." A good workout or walk can also ease that uptight feeling. Exercise is a natural tranquilizer and antidepressant. It releases in the brain , beta-endorphin, a hormone with effects similar to those of valium and morphine.
Dr. Herbert A deVries,Director of Exercise Research Laboratory at the University of California, found another benefit. He conducted experiments that showed a brisk walk, increasing the heart rate to 100 beats a minute, decreased the electrical activity of muscles by 20 per cent.
Exercise keeps the body well-oiled which is believed to provide protection against heart attacks. High blood cholesterol levels are often associated with atherosclerosis which, acting like a clogged drainpipe, can stop blood flowing to the heart. Exercise increases the high density lipoproteins, the good cholesterol, that clears the blood of excess cholesterol. It also makes blood platelets more greasy and less likely to form a clot in coronary arteries.
Activity makes the heart a more efficient pump. Sedentary individuals, according to Dr. Harvey Simon of the Harvard Medical School, face twice the risk of heart attack. They are also less likely to survive one.
Jogging, swimming, bicycling and aerobic exercises carried out three times a week lower blood pressure. How much exercise is needed varies from patient to patient. The greatest decrease in pressure of 10 to 20 per cent, were seen in patients who had never taken drugs for hypertension and in those with an overactive nervous system.
Exercise helps to prevent non-insulin dependent diabetes. It combats
this lifestyle disease by fighting obesity. Today 90 per cent of diabetes is caused by obesity. Exercise helps to shed excess pounds, increases the body's tolerance to glucose and increases the efficiency of insulin, the hormone produced by the pancreas.
Activity helps to ward off osteoporosis. There's been much written about how estrogen prevents this disease in postmenopausal women and why calcium is needed for both sexes. But more than estrogen and calcium is required to prevent osteoporosis. Ralph La Forge, Director of Preventive Medicine at the Sharp Memorial Hospital in San Diego, says, " This approach is like adding fuel to the carburetor without increasing the speed of the engine, it just goes to waste."
He explains," Adding more calcium to your diet won't necessarily result in deposition of more calcium in bones unless you also create a demand in the bones for more calcium. One way to do this is through regular weight-bearing exercise." Studies show that the mineral density of bone is 40 per cent greater in those who run than in others who don't.
Remember that just one week in bed results in the loss of one per cent of a person's bone mass. This is why astronauts lose bone mass in a weightless atmosphere. Why swimmers supported by water have less bone mass than weight-lifters. You have to be planted on your two feet to achieve the right balance of stress. And the safest, and one of the best, exercises is walking which also keeps the joints mobile.
Can regular activity decrease the chance of cancer? Dr. Steven Blair of the Institute of Aerobics in Dallas investigated the incidence of cancer among 250,000 U.S. war veterans. His findings revealed that men employed in physically demanding work were less likely to develop cancer of the large bowel, brain, kidney or leukemia. And it has been suggested that active women have a decreased risk of breast malignancy due to lower levels of the hormone estrogen.
Dr. Blair admits this finding may be a casual relationship which means nothing. There is a casual relationship as well between the sun rising every morning and our getting out of bed. But we do know that inactive people often suffer from constipation. This allows fecal matter containing cancer causing substances to remain in contact longer with the bowel's lining. Active individuals with normal bowel movements get rid of these carcinogens more quickly.
Hippocrates observed 2000 years ago," That which is used develops. That which is not used wastes away." It's still sound advice. People who use elevators to go up one floor and who step on escalators to go down one flight should listen to the Father of Medicine. It's far better to wear out than rust out.
W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of The Harvard Medical School. He's been a ship's surgeon, hotel physician and family doctor and later trained in surgery at McGill in Montreal, University of Rochester N.Y. and Harvard. His medical column is published by 60 Canadian newspapers and several in the U.S. He is the author of seven books. Dr. Walker has a medical practice in Toronto. His Web site is: www.mydoctor.ca/gifford-jones. He can be reached at letters@canadafreepress.com
