The boom in research regarding the benefits of exercise has unveiled yet another positive outcome: Regular exercise can help prevent sudden cardiac arrest, particularly if it's kept up over an extended period of time.

According to a study, women who exercised less than two hours a week, if at all, faced an overall six-fold increase in the risk of sudden cardiac death during a rare workout session, and for up to an hour afterward. However, women who exercised anywhere from four to seven hours a week cut their chances of a sudden cardiac episode by half.

What is sudden cardiac death, exactly? For starters, it's not a heart attack. During a sudden cardiac episode, the heart just stops. And while this is linked to irregular heartbeat, doctors often don't know the true underlying cause.

The Exercise Effect

Researchers gathered data from nearly 70,000 women without any history of heart disease or stroke at the start of a study that spanned 18 years (from 1986-2004). In the years between, 140 women in the study died from sudden cardiac death. Why?

• Sedentary women were nearly 21 times more susceptible to sudden cardiac death.

• Women who exercised more than two hours a week drastically reduced their odds to about three times less risk.

• The odds of sudden cardiac death dropped anywhere from 10 percent (two to four hours a week) to 56 percent (four to seven hours) to 69 percent (more than seven hours), as women devoted more time to exercise.

• The threshold for heart-healthy benefits of exercise gained momentum when women exercised for more than four hours a week; risks for sudden cardiac death began to noticeably decline.

An expert warning: While moderate to vigorous exercise provides health benefits, those who haven't been regularly active should start off slowly, and for most, it's a good idea to check with a physician before staring a regular program.

Forbes May 6, 2005

Dr. Mercola's Comments:

There has certainly been a recent surge in research on the benefits of exercise. The common thread that links virtually all of these studies: To enjoy any protective benefits from exercise, it's important to get enough in, and to do it regularly. An interesting point this study illustrates is that, even though sudden cardiac death typically occurs during a bout of exercise, increasing your frequency of exercise sessions per week actually lowers your risk. In other words, even though it seems as though you are adding to your risk of dying from sudden cardiac death by performing the very activity during which it occurs, more often, the reverse is actually true! While this may seem obvious, that hasn't always been the case. My mentor in exercise, Dr. Ken Cooper, was the pioneer in abolishing this myth. Prior to his information crusade, most all cardiologists would put patients at bed rest after a heart attack. Now, of course, that would be grounds for malpractice. Of course, the benefits that you derive from regular exercise extend far beyond its lowering of your risk for sudden cardiac death. The wide range of positive effects that exercise can have on your mind and body include, but are not limited to: Weight control Better sleep Less pain Improved immune system function Less chronic disease Improved mental function Better mood Fortunately, there are a number of free resources available on this site that can help get you started today. Some of the best information we have to offer has been contributed by Paul Chek and Ben Lerner. Related Articles: The Ultimate Drug For Heart Disease 10-Minute Exercise Schedule Good for Your Heart Walking Not Enough to Prevent Heart Attacks