What if there was a safe and scientifically proven treatment that reduced your risk of cancer, heart disease, osteoporosis, and other conditions? What if you only had to "take" it once a day, or even less often? Would you pay $50 a month for this? Would you pay $100? Would you travel miles to receive this potion?

How much would the pharmaceutical companies charge for this "magic elixir"? Would they be able to produce enough of it? What would happen to the stock price of the company that discovered this?

What if I told you that this elixir exists, that it's free, or at least inexpensive? It's called physical activity, or more commonly, exercise.

Yes, exercise has been repeatedly shown to be effective as prevention for many common and serious diseases. For example, those who lead a "sedentary" lifestyle are nearly twice as likely as those who are "active" to develop coronary disease (narrowing of the blood vessels to the heart that can cause a heart attack). The risk of developing hypertension (high blood pressure) is 30-50%higher in inactive persons than in those who are active.

Data from a study with the clever acronym "MRFIT" (or Multiple Risk Factor Intervention Trial) showed that men who had thirty minutes a day of moderate physical activity, such as walking, had a 20% lower mortality rate than less active men.

Physical activity may reduce the risk of colon cancer, as well. Activity may help to shorten intestinal transit time and thus reduce exposure of the intestines to cancer promoting agents.

Aerobic exercise has been shown to relieve symptoms of panic disorder. One study showed that individuals who ran or walked a four-mile course several days a week required less medication to achieve improvement in symptoms.

Maintaining a health and attractive weight is a struggle for many people. Studies have repeatedly demonstrated that regular exercise is a key component of losing weight and keeping the weight off. '"Yo-yo" dieting is dangerous and unsuccessful; people need to increase their activity and therefore their metabolism to keep weight off.

Insomnia is a multi-billion-dollar problem in this country. People use a variety of over-the-counter and prescription medications for this condition. Exercise has been shown to be very effective in reducing insomnia, especially as we get older. Just be careful to avoid exercising too close to your bedtime.

A study in the New England Journal of Medicine in May 1997 demonstrated that physical activity during leisure time and at work is associated with a reduced risk of breast cancer. I can't think of a more frightening disease for women than breast cancer. In regularly exercising women, the reduction in risk was even greater in younger women (less than 45 at entry into the study).

Many people with arthritis are afraid to exercise because of pain and concern that exercise may worsen their condition. However, experts in the field recommend gentle exercise for arthritis, such as aquatic exercise. Patients with arthritis often get caught in a cycle of inactivity and need to increase their level of activity, albeit slowly.

Both pre- and post-menopausal women can reduce their risk of devastating hip fractures and the stooped posture with compression fractures by making their bones stronger through regular weight-bearing exercise. Walking is an ideal start and strength training with weight may also be a consideration. Men are also at risk for osteoporosis as they get older and this applies to men as well.

To summarize, exercise has been shown to reduce the risk of coronary artery disease, improve cholesterol levels (especially increasing the good HDL cholesterol), lower or prevent high blood pressure, reduce the risk of colon and breast cancer, prevent or control adult onset diabetes, promote weight loss and help keep the weight off, protect against osteoporosis, improve mood and reduce anxiety and depression, reduce insomnia, improve mental alertness. Wow, if that list doesn't exhaust you, you must be in good shape!

So what do you need to do? You need to starting getting more physically active. If you're inactive, you need to get motivated and start walking and doing exercise. Try to shoot for four times a week. At least three will give you some benefit. Join a gym (and use it!), get some good walking shoes, meet with a personal trainer, find a partner. Start exercising!