Now for the good news – the benefits of exercise.

• Lower risk of coronary heart disease: As we have seen, those who are physically active have about a 50 per cent reduction in risk compared with those who are inactive.
• Stronger heart: A well-conditioned heart will pump the same amount of blood in 50 beats each minute as the inactive person’s heart pumps in 70 to 75 beats. Compared to the well-conditioned heart, the inactive person’s heart has to pumps up to 15,000 more times per day – more than half a million times each year!
• Lower risk of cancer: Exercise may help to protect women against various forms of cancer, particularly of the breast, ovary, cervix, uterus and bowel.
• Preservation of bone density: Osteoporosis is a particular problem in women after the menopause. Hormone Replacement Therapy (HRT) has been shown to protect women against bone loss, but there is also good evidence that regular, weight bearing exercise, can help to preserve healthy bone density. Women who remain physically active into old age are much less likely to suffer from osteoporosis.
• Reduced blood pressure: Physically active women have lower blood pressures than women who are inactive and unfit. This beneficial effect is one of the mechanisms by which exercise helps to protect against heart disease.
• Reduced body weight: Regular exercise helps to promote fat loss, whilst improving muscular strength and flexibility. By burning calories more efficiently and helping to preserve muscle tissue, regular exercise helps to maintain a healthy body weight.
• Increased HDL-Cholesterol: Exercise has almost no effect on either total cholesterol or LDL-cholesterol, so the idea that you can just ‘burn off’ excess blood cholesterol just isn’t true. Exercise does, however, raise the level of HDL-C, which helps to protect against heart disease. Although the rise in HDL-C produced by exercise is, on average, quite small, this has a large impact on heart attack risk.
• Reduced clotting tendency: An increased tendency for blood to coagulate is an important factor in precipitating heart attacks. One measure of the clotting tendency is the level of a substance in the blood called fibrinogen; the higher the blood fibrinogen, the greater the risk of thrombosis (See Chapter 3). Exercise reduces blood fibrinogen levels, and therefore the risk of heart attack. Another important factor is the effect of exercise on blood platelets. These are small particles in the blood, which prevent bleeding from cuts or broken blood vessels by clumping together and initiating the formation of a blood clot. Sometimes platelets mistake the fatty plaque inside a diseased coronary artery as a break in the vessel wall that needs plugging, and in doing so precipitate a clot and a heart attack – hence the term ‘coronary thrombosis’. Exercise has been shown to reduce platelet stickiness by up to 40 per cent, and thus reduce the risk of a heart attack.
• Reduced risk of diabetes: Maturity-onset or non-insulin dependent diabetes (NIDDM) usually appears after the age of 40. Unlike those with juvenile onset diabetes, whose bodies do not manufacture any insulin at all, those with NIDDM continue to secrete some insulin, but the body appears to be more resistant to its effects.
  Many studies have shown that regular physical activity is associated with a reduced risk of NIDDM. Exercise reduces insulin resistance and helps to restore the body’s ability to handle blood sugar normally. Even younger diabetics who use insulin can benefit from regular exercise. Apart from improving their fitness they will tend to see a reduction in their daily insulin requirements. However, exercise can be hazardous if taken too close to an insulin injection and diabetics need to achieve close control over their blood sugar levels if they are to avoid problems.
• Improved aerobic fitness: Regular exercise – particularly of the aerobic variety – strengthens the heart and improves the efficiency of the heart and lungs. Obviously, if you exercise regularly then your general level of fitness will be much higher than a sedentary individual. Not only does this reduce your risk of developing many forms of disease, it also adds immeasurably to the quality of life.
• Reduced stress and improved moods: Prolonged exposure to stress hormones such as adrenaline can increase the pulse rate, blood pressure, blood fats and blood sugar and may be harmful to health. There is evidence that regular exercise can help to reduce the sudden hormonal surges typical of the stress response.
  In addition, people who take regular exercise report less depression and fatigue and they also have better sleep patterns. Precisely why exercise should have such beneficial psychological effects is not entirely clear, but it seems that a special group of chemicals ‘endorphins’, play a part in this. These substances have a chemical structure similar to morphine and may, therefore, act as the body’s ‘natural’ painkiller. Exercise is known to increase endorphin levels and this may explain why exercise improves the mood, reduces anxiety and combats the symptoms of pre-menstrual tension.
• Improved sleeping pattern: Insomnia is an increasingly common complaint and most of us have experienced occasional sleepless nights from time to time. For some people such difficulties can evolve into a chronic sleeping problem. Regular physical exercise can do much to help restore a normal sleeping pattern by promoting more continuous and restful sleep; it should be an integral part of any strategy for dealing with insomnia.

I think you will agree that - by any measure - this is a pretty impressive list of real benefits that you can achieve by regular, moderate exercise.