A word of caution about exercise

Some sad news from the running world this past weekend: Three men died while competing in a marathon in Detroit on Sunday. The men collapsed within 16 minutes of one another between the 11-mile and 13.1-mile markers. The causes of their deaths have not yet been determined.

I mention this incident because exercise, while having the potential to benefit nearly everyone, is not without its dangers, particularly for those with undetected heart disease. An estimated 75,000 heart attacks occur in the U.S. each year after heavy exertion.

That's why it is always a good idea to confer with your doctor before beginning a program of strenuous exercise, especially if you have two or more risk factors for coronary heart disease.

Deaths in marathons and other road races are relatively uncommon. The Detroit Free Press/Flagstar Marathon last had a fatality in 1994, when a 42-year-old man suffered a heart attack, according to the Associated Press. More than 19,000 people had registered for Sunday's race, and presumably most of them finished safely.

A thorough physical examination and exercise stress test might seem unnecessary or inconvenient should you ever be asked to undergo them before beginning an exercise program, but they are for your own protection and benefit.

Coronary heart disease is the number-one cause of death in the United States, and there's an old saying that explains why it has achieved that dubious status:

Often, the first symptom of heart disease is death.