Keeping fit can "reduce your risk of developing long-term disease, increase your life expectancy, and improve your quality of life in later years"1. It reduces the risk of coronary heart disease in particular and "can also help to lower your blood pressure, improve your cholesterol level, control your weight and reduce your risk of diabetes. Physical activity is also a good way of relieving stress"2. Keeping fit makes pregnancy easier, and complications less likely3. Exercise also aids mental health1,4,5. Research is showing that physical exercise allows the brain to retain its effectiveness longer into old age4,6 and even when starting after a life of sloth, exercise can help rescue the brain from mental decline, stimulating the growth of new neurones7. A healthy lifestyle, including physical fitness and eating sensibly, "can significantly reduce a person's risk of developing dementia"8.
Lack of physical fitness is not just to the individual's detriment, but has a negative impact on national economic efficiency and causes increases in national health costs. A lot of very expensive long-term therapies can be avoided simply by keeping fit in life. Exercise can be done for free in the home, with no equipment at all. Also with access to the Internet, it is easy to find many session videos to provide instruction. Finally, the Family Doctor Home Advisor gives some guidance: "Start by setting realistic goals. If you are not fit, begin exercising slowly and build up gradually"1.9
“Aerobic exercise can improve cognitive function, perhaps because of the increased oxygen to the brain or a rise in glucose metabolism. [...] A person who exercises consistently over a period of years will not show the same mental decline as someone who doesn't exercise. In tests of rapid decision making (such as how quickly a person could slam on the brakes if a child jumped in front of his or her car), researchers found that older men who had exercised were better at quick decision making than older men who hadn't. It is known that those who exercise for a long period have healthier hearts, lungs and muscles; now scientists suspect that exercise might also slow the decline in central nervous-system processing as well. Even walking around the block has been shown to be beneficial.
There's now solid evidence than regular aerobic exercise (such as running, biking, or swimming) can ease some more moderate cases of depression by raising the level of certain brain chemicals responsible for mood - some of the same brain chemicals that are affected by antidepressants. Even a brisk midday walk for 10 to 20 minutes can help. To be most effective, a person should exercise regularly at least three times a week (five or more is better) for at least a half-hour each time.”
“If you are reasonably fit you will cope more easily with the experience [of pregnancy]. [...] All these changes put extra stress on your system. [...] If you are in good shape, however, you are likely to take it all in your stride, and you will find that your life will go on much as usual. [...] Healthy muscles, good circulation (which results from doing physical exercise) and posture all reduce the discomforts of being pregnant.”
About one third of the global population is overweight or obese10. Most Western countries are facing an obesity epidemic. Our cultures are having to change to compensate for widespread ill-health. It is costing our health systems a massive amount of money, and is having negative effects on national economies. The situation has persisted for a suitable length of time for our very perceptions to change; opinions on "normal weights" for people and "average sizes" for clothes has shot up11. Over 2 in 3 adults in the UK are overweight11 and this costs the NHS £5.1 billion per year12 and "costs Britain's economy £47bn a year; more than war, terrorism or armed violence"13. We are forgetting how to be healthy.
The causes are not genetic. Most people who say obesity "runs in their family" are wrong. The rate of increase in obesity is many, many times too fast to be accounted for by a change in inherited genes14. Our culture and lifestyle choices are to blame. The causes of the modern obesity epidemic are processed foods, low levels of physical exercise, over-indulgence, poor choices in food products, poor knowledge of nutrition. Most of this is made much worse by well-funded advertising campaigns by food manufacturers selling cheaper mass-produced food. Even some so-called "health foods" contain well over recommended limits of fat, salt and sugar15.