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The Exercise Myth
Part 3: The Dangers of Exercise
Exercising faith
In June 1991 the British government published its initial Health of the Nation green paper. In it, exercise was promoted on the grounds that it prevented heart disease. Given that a major national effort is invested in promoting exercise on the grounds that it prevents heart disease, you might think it fair to ask for some evidence to substantiate this claim. So the British Medical Journal conducted a debate into the merits of the green paper and contested the assertion that exercise was helpful. This led to two contributors to the debate revealing the anti-scientific mentality of the health promotion lobby. In their support of ‘the role of exercise’, Drs. Henry Dargie and S. Grant took on the exercise sceptics by writing:
‘Some would argue that there is no conclusive evidence from controlled trials that regular exercise reduces the number of deaths from coronary heart disease or substantially prolongs life. To demand such proof is to miss the point about exercise, which is that it is valuable for numerous other health benefits it confers and as a catalyst in the adoption of a healthier lifestyle.’[18]
So it seems there is no evidence after all on the benefits of exercise in heart disease — merely ‘numerous other health benefits’. No doubt to request evidence for these benefits would also be to miss the point, which is that the health promoters firmly believe that exercise is conducive to a healthier lifestyle. It seems it is faith rather than science that justifies exhortations to change public behaviour. And such faith may place a trusting public at greater danger, for exercise is not always be beneficial.
The dangers of over-exercising
‘Fitness’ is a billion-pound industry which promotes books, exercise machinery, weights, footwear, clothing, and expensive gyms and clubs. If someone tells you that you need to exercise, you would be wise to question whether there is any commercial bias behind their advice.
Sport and exercise of the right kind can be rewarding both as a social outlet and in making you feel good, it may boost your self-esteem if you treat it as a form of group therapy, and it helps to keep muscles in trim and give your body a better shape. As such it has an important role to play, particularly as leisure time for most of us is increasing. But it can easily be overdone with potentially disastrous consequences.
In women, exercise exhaustive enough to cause weight loss can delay the onset of puberty, cause amenorrhoea (cessation of periods), abnormal menstrual cycles, abnormal sex hormone patterns and impaired reproductive function, and the early development of osteoporosis.[19] [20] [21] Male long-distance runners may suffer reductions in the male sex hormone, testosterone.[22] For anyone contemplating taking up the more strenuous forms of exercise, the advice from the American Heart Journal is:
‘Be tested and have an exercise programme devised after clinical trials and tests on the heart as, although regular exercise will lower the overall risk of cardiovascular disease, there is a statistically significant increase in the risk of sudden death.’[23]
There are real risks if those who are not seasoned athletes attempt to break through the pain barrier, or as Jane Fonda puts it, ‘go for the burn’. The pain barrier is the body’s signal that its limit of toleration has been reached. Disregarding it is foolhardy. While seasoned athletes with their increased oxygenating capacity may be able to prolong their muscular activity before the onset of pain, the average person cannot and should not attempt to emulate them. The risk to health and even life is unacceptably high. Over the past few years there have been reports of significant numbers of cases of sudden death in healthy young men out jogging or playing squash because they disregarded the pain barrier.
Most sudden deaths in sport are caused by cardiovascular conditions, although one regularly hears that the benefits of exercise in terms of CHD are ‘well established’ and may reduce the risk of such events. Victims are often perceived as very fit but it should be noted that ‘extreme forms of conditioning, including marathon running, do not prevent severe atherosclerosis or sudden death.’[24]
There have also been a huge number of cases of broken bones, dislocations, and damage to internal organs, muscles, tendons and ligaments. A study from Japan cited a 25% incidence of injury in those undertaking exhaustive exercise and these figures are confirmed in similar Western studies. The increase of sports-related injuries has been such that, had they been caused by a bacterium, it would have been classed as a serious epidemic.
Exercise-induced allergies — asthma, skin itching and urticaria (nettle rash) — are also on the increase, as are cases of cardiovascular collapse and respiratory obstruction.[25] While some conditions may be minor annoyances, others are definitely life threatening. They typically affect teenagers and young adults.
In a study of 42 Swedish elite runners, 23 had asthma and 31 had asthma-like symptoms. The prevalence of asthma in elite athletes in Finland whose mean age was 22.9 was similar. Of 103 athletes, 16 had documented asthma and 24 more had allergies. All of those with asthma and 14 of those with allergies reported having symptoms like exercise-induced asthma. Twenty-three of the remaining 63 also reported having asthma-like symptoms occasionally. Thus over half of the runners in this study were affected.[26]
The usual trigger for an attack is running, but some patients have collapsed after only a brisk walk. It is not possible to predict an attack even among people with a history of such attacks while running. Even joggers, who have been running for many years without incident, frequently collapse. Jim Fixx, author of The Complete Book of Running, invented jogging and advocated it to prevent a heart attack. It is ironic that Fixx, himself, died of a heart attack while out jogging. Current advice to joggers is: never jog alone.
In spite of the risks, or more probably because they are not made aware of them, many people adopt exercise programmes which involve sudden intensive exertion such as squash or aerobics.
The term aerobics means ‘using oxygen’ and it is claimed that aerobic exercise is beneficial because it increases the amount of oxygen in the body tissues. In fact, the demand for oxygen may increase to a point where it cannot be met, so that, far from increasing tissue oxygenation, aerobic exercise decreases it. Aerobic exercise has been demonstrated to cause a significant and continuous drop in blood pressure — a sign of cardiac fatigue.[27] It can happen in as little as 5 minutes — and most aerobic sessions last for an hour!
There is another consideration, particularly where the overweight are concerned: by definition, people who are overweight are already carrying around extra weight. That fact alone means that they must already use more energy than slim people. There is a limit to how much more exercise someone who is massively overweight can do.
Athletes reach altered states such as ‘the runner’s high’. It makes them feel better and is a form of reward for their effort. The lower potential of overweight people means that they will be denied this satisfaction even if they do lose some weight.
Too much of a good thing?
The reason we have the potential for rapid movement is that we have evolved to be able to escape from danger and to survive in a wide range of dangerous and adverse circumstances. This ability is built into our bodies’ emergency system: the ‘fight or flight reflex’. Activated by the need to run away from danger or stay and fight, or as a result of strenuous exercise, this reflex causes a number of automatic responses which prepare the body to face the danger to come: the heartbeat is accelerated; minor blood vessels are constricted so that more blood is fed to the brain and muscles; the lungs take in more oxygen; the amount of cholesterol in the blood is increased; adrenaline is pumped into the bloodstream helping these changes, stopping or slowing the digestive process, and stimulating the conversion of glycogen, a form of sugar stored by the body, into glucose which the body can use more easily as a source of energy.
These changes, in the natural world, are designed to last for a short time: the time of the emergency, after which the body can return to normal. In the case of prolonged physical exertion, however, the body is forced to continue, setting in motion a series of changes called the General Adaption Syndrome. A major and important change is the prolonged production of a group of adrenal hormones called corticosteroids. An excessive production of corticosteroids has been shown to produce heart disease,[28] hypertension and stomach ulcers,[29] and harm the body’s ability to fight infectious diseases and cancer;[30] the depletion of the corticosteroids may also cause rheumatoid arthritis.[31]
Other evidence had emerged in 2005 which suggested that exercising may actually shorten your life.[32] Dr Peter Axt and his daughter, Dr Michaela Axt-Gadermann, who are both reformed long-distance runners, argue that exercising increases the production of harmful free radicals — unstable oxygen molecules believed to speed up the ageing process. They say: ‘If you lead a stressful life and exercise excessively, your body produces hormones which lead to high blood pressure and can damage your heart and arteries.’
The correct exercise for health
I hope by writing some of the information above that I haven’t put you off exercising altogether. That was not my intention as there are numerous benefits to health and well-being from exercise — if it is approached in the right way. I wrote it because there are two aspects to exercise: one is health, which I have covered above; the other is fitness. ‘Health’ and ‘fitness’ are not synonymous. There is not a great deal of evidence that exercise plays much part in health — unless you eat an unhealthy, ‘healthy’ diet — but exercise of the right kind will keep you fit: that is supple, strong and with stamina.
For health generally all that is necessary is moderate exercise. To increase the capacity of your cardiovascular system, you need to work harder. But either way, it’s a good idea to avoid repetitive ‘bouncing’ types of exercise that shock the system. This means that walking, cycling and swimming are good, but running and jogging are not.
Conclusion
People with only ten pounds or so to lose may be able to lose it with exercise. But anyone who claims that exercise is the key to solving weight problems in the chronically obese is simply not telling the complete truth about what research on the subject has shown.
What population studies of active people have shown they have in common is their low-carbohydrate diet. Fat is the best fuel for an athlete, carbohydrates are the worst. The same goes for weight loss. It really is as simple as that.
To sum up, moderate exercise and sport do have a healthy social role. However, excessive exercise is unnatural and can be dangerous. Don’t be misled by the hype — athletes are not known for their longevity.
Part 1: Exercise for weight loss | Part 2: Exercise and heart disease | Part 3: Dangers of Exercise | Part 4: References
Last updated 6 February 2010
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