Is physical exercise healthy? Most people believe it is and assume that a person has most chance of a long life if he or she engages in a lot of it. It is by no means certain, however, that physical activity and health are indissolubly linked. The only thing which can be said with any certainty is that regular physical exercise reduces the chance of disorders affecting the heart and circulation. In the case of older people, it is not easy to determine what intensity of physical activity can best be chosen in order to produce favourable effects on the body. Is a daily walk sufficient or is competition needed in order to raise the level of performance? The choice is not a simple one.
Physical activity plays a part in ‘mental health1, too. Everyone has his or her own reason for engaging in physical exercise; one person does it to work off tensions, another for the feeling of satisfaction which it gives to have achieved a certain performance. Physical activity has also come to have an important social significance in our society where there is a growing appreciation of leisure time.
Since the late 1960s fitness has developed into a cult. More and more people are jogging, cycling, exercising at home or attending a sports centre, or if they are not taking exercise, at least they feel that they ought to be doing so.
The rise of the fitness craze has coincided with an increase in a general interest in health and probably rests on the misconception that exercise is by definition healthy.
What is condition?
Condition, or fitness, might be defined as the physical capacity to meet the demands made by oneself or one’s environment. As these demands differ from individual to individual, so too does the degree of fitness needed.
A policeman who regularly has to deal with emergencies requires a higher level of fitness than someone who drives to work every morning and spends the rest of the day sitting at a desk.
Aside from a person’s constitution, condition de-pends chiefly on the amount of physical exercise performed in the past month.
Getting in condition
One of the most important characteristics of any living organism is that it adapts itself to its circumstances. Consequently, the only way to become fitter is to increase the amount and/or change the type of exer-cise. A person who starts running a kilometre in six minutes every day will become fitter at first quite rapidly, and in roughly four weeks’s time will have attained about 80% of his or her potential; by the end of about two months the body will have adapted itself to this amount of exertion and no further improvement will take place. To become even fitter it is necessary to increase the speed, the distance or both. Adaption in the reverse direction occurs at the same rate. A person who is suddenly confined to bed will have lost 80% of his or her fitness by the end of a month.
Levels of fitness
There are three different levels at which one can be sufficiently fit. Which level a particular individual requires depends on what he or she wants. For a person who abhors exercise and is not engaged in anything that necessitates more than minimum fitness, the lowest level is sufficient. However, as body functions deteriorate if they are not used (an example is the muscular atrophy which occurs when an arm or leg has been in a cast for a few weeks) a certain amount of exercise is needed to maintain this minimum level. Many people receive the minimum amount from their normal activities: most types of physical work in the home or the garden, or a hobby, and everyday activities such as walking to the office or the shops are generally sufficient.
Tips for maintaining the minimum fitness level: . bend, twist and/or stretch your joints almost to their maximum extent every day; . stand or move for a total of two hours a day; . lift a heavy weight for five seconds every day; . raise your heartbeat to 120 beats a minute for at least three minutes every day; . use up 300 Calories a day in physical exercise. At the second level of fitness, the normal daily activities can be performed without excessive fatique and a reserve is available for unexpected events. Some special light fitness programme is necessary to maintain this.
The third fitness level is needed for strenuous activities such as sport or heavy work. Regular energetic physical exercise is an essential part of keep fit at this third level.
Exercise and health
In most people, of course, exercise and health are associated, although one is not necessarily caused by the other. Exercise can even impair health. This is obvious in the case of a physical accident that results from sporting activity. More serious are injuries to bones and joints, caused by running on hard surfaces, or a strain of the heart, perhaps resulting from exer-cising too much too soon in over-eagerness to get fit. Women who have started too young with training may find their normal hormonal metabolism is disrupted, which may result in amenorrhoea and associated physiological problems.
Condition and health
Condition is also not synonymous with health. Nevertheless, in general, to be in condition one must be in good health, though there are innumerable examples of top sportsmen turning in excellent performances when they were sick. Conversely, it is possible to be healthy but badly out of condition.Can exercise make you healthy? Certainly sometimes but not always: you have only to think of the enormous numbers of inju-ries and even cases of permanent invalidity which result from engaging in sports. If the risk of disease can be reduced by exercise, however, probably the only category of disease that definitely benefits is that of cardiovascular diseases. There are as yet no clear indications either that active people live longer than people who are not active. If one looks, however, not merely at age but also at the way in which people grow old, those who keep themselves in condition clearly have an advantage, because they have sufficient reserves to compensate for the natural deterioration in body functions. The most important contribution to health made by physical exercise probably lies in the pleasure that people derive from being physically active and the mental relaxation it brings about. The feeling of satisfaction almost everyone experiences after having successfully overcome a self-imposed physical effort gives many sufficient strength even to give up use of alcohol and tobacco.
Fitness, or condition, training is aimed at improving or maintaining a person’s level of fitness. In principle any form of physical exercise is suitable for the purpose. However, some forms (for example, popular activities such as walking, running, cycling and swimming) have a more general effect on condition than others. General fitness involves the all-round development of all sorts of body functions, including muscle power, stamina, blood circulation and respiration. Specific fitness is concerned with the development of those properties that are needed for a particular activity. For example a person who wants to take a skiing holiday should be in good general condition, but he or she should also do exercises that are specifi-cally geared to this sport.
Fitness training begins the moment you make more than your usual amount of physical effort. For it to have a lasting effect, however, you must train regularly (about three times a week at least) and for a sufficient period of time (on average, at least a quarter of an hour). Many fitness programmes are based on performances: for example, running a cer-tain distance in a certain time. What is important, however, is not performance itself (unless competition is the object) but whether the effort made is sufficient to bring about changes in the body. Whether a given performance requires sufficient effort depends on a person’s condition. The only way of knowing whether you are making the proper amount of effort is to measure it directly. Heart rate affords the easiest means of doing this. The fitter you become, the greater will be the performance needed to attain the required heart rate.
The level of fitness that a person can attain depends on the age at which he or she commences training. To reach the highest level he or she would have to start training around the age often and continue without interruption until peak performance is reached. At whatever age one begins however, training will always bring an improvement in physical condition. If you have been inactive for a long time, however, and are over 35 years of age, it is advisable to have yourself examined by your doctor before embarking on fitness training.
What are the risks?
People have suffered heart attacks while running marathons or playing squash. But these activities are particularly vigorous and neither should be considered without previous regular training or at-tempted in extreme weather conditions. Accidents caused by sensible exercise are rare. The important thing is to build up your exercise programme gradually, starting with a very low activity-level.