Despite all the miracle drugs, surgical techniques, and modern equipment that medical science uses, the most effective key to good health is still people's everyday behavior.

Moderate exercise, no smoking, balanced diet, and weight watching are the behaviors that lengthen life, avert many diseases, and offer better chances of health and vigor. Add to those, periodic checks for high blood pressure and high cholesterol, the common indicators of potential stroke or heart attack.That combination, which is not all that complicated, offers the best hope to drastically reduce heart disease, particularly ischemic heart disease - the clogging of blood vessels that feed the heart.

As the American Heart Association pointed out a few days ago, the healthier living habits adopted by many Americans are largely credited with an astounding 25 percent drop in deaths from heart and blood vessel disease in the past 10 years. Better living habits by more people could cut even further into the one-million who still die each year in the United States of heart problems.

How widespread are heart problems? Health statistics show that one in every four Americans has some form of heart or blood vessel disease and about half eventually die from it.

While new drugs and new surgical methods can play a part in improving the treatment of heart ailments, the biggest and quickest success - as heart specialists point out - can still come from encouraging people to take better care of themselves. Improved behavior alone could still cut the existing heart disease death rate by 400,000 or more people a year. Unfortunately, so many people insist on being their own worst enemies.

Exercise, eat prudently, don't smoke, and watch the weight and blood pressure - what simple things to save so many lives.