EXERCISE AND CORONARY RISK FACTORS

There is a good deal of evidence to show that regular exercise helps protect an individual against coronary heart disease. Several studies of men in different occupations have shown that coronary heart disease is more common in the less active than in the more active. There is also recent evidence which suggests that exercise lowers the level of LDL lipoproteins (the lipoproteins that promote arteriosclerosis) and increases the level of HDL lipoproteins (the protective type of cholesterol).

Australians pride themselves on being a sporting nation, but the average Australian doesn't engage in much exercise. The National Heart Foundation's Risk Factor Prevalence Study mentioned earlier found that only 35 per cent of men and 27 per cent of women had engaged in vigorous exercise in the fortnight before they were interviewed. Only one in ten men and one in 20 women exercised vigorously three or more times a week during this period, which is the minimum average level recommended by the National Heart Foundation to maintain adequate heart, lung and muscle fitness.

Strenuous exercise appears to be particularly effective in protecting against fatal heart attacks. But people unused to strenuous exercise need to work up to it gradually, and older people need a medical clearance first.

The heart's capacity for work can be increased with physical training. Training also improves the circulation of blood to muscles and the muscles' efficiency in burning fat. One effect of training is to lower the heart rate at rest. This creates more scope for increased output, if needed. Not all forms of exercise, however, are equally as effective. Walking, swimming, running and cycling are all good exercises for the cardiovascular system. They are preferable to isometric exercises such as weight-lifting or press-ups.

Exercises should be performed regularly and as often as possible They should be strenuous enough to cause breathlessness and sweating, and you should work up to your optimum level gradually over a period of eight to ten weeks. The aim, if you are overweight, should be to use up at least an extra 2000 calories a week (about 300 calories a day which is equivalent in food terms to three slices of toast and a tablespoon of butter).

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