What is the best way to prevent heart disease, diabetes and obesity? Medical experts repeat their answer like a mantra: regular, continuous exercise. Daily endurance exercise has for years been promoted as the key to long-term health, but new research suggests that more frequent shorter bursts of intense exercise may be just as good, maybe even better.

The classic health recommendation has been 20 to 60 minutes of continuous, vigorous exercise every day or nearly every day. According to a new study, however, intermittent exercise may be more effective at clearing artery-blocking fat from the bloodstream than continuous exercise. Buildup of his kind of fat is a known contributor to coronary artery disease and other serious health problems.

Researchers looked at the effects of continuous versus intermittent exercise on levels of triglyceride, a type of fat, in the bloodstream after subjects ate high-fat meals. They found that people who put in 30 total minutes of exercise a day can achieve lower triglyceride levels if they break it up into short, separate bouts of exercise — such as three 10-minute sessions per day — instead of one 30-minute session.

"Most Americans who exercise are exercising around 30 minutes a day," said researcher Tom Thomas of the University of Missouri-Columbia, "Based on the results of the research, the intermittent approach would probably be best for most Americans at lowering fat in the bloodstream."

The study, which was published in the August issue of Medicine & Science in Sports & Exercise, also found that it makes a big difference when you exercise. Exercising before eating is crucial for fat clearing, perhaps because muscle contraction during exercise stimulates the body's production of a fat-clearing enzyme. This kind of enzyme activity seems to peak about 12 hours after an exercise session, meaning that people who eat large breakfasts could benefit more from evening exercise, while those who eat large dinners could benefit more from exercise in the morning. However you choose to exercise, it is still important to exercise every day, because the exercise effect on fat clearing lasts no longer than 24 hours.

Asked for comment by TheDoctor, Harry Pino, Ph.D., Exercise Physiologist with the Obesity Consult Center at Tufts-New England Medical Center said, "The key to a successful exercise program is consistency and regularity. We recommend accumulating at least 150 minutes of exercise each week. This can be achieved in 30-minute continuous sessions daily for 5 days per week, or by breaking the sessions up into shorter bouts of activity each day. The key with the shorter workout approach is that you should do a minimum of 10 minutes of activity at a time. That way, if you exercise three times per day, 5 days per week, you will get your 150 minutes per week. Either approach can help you achieve weight reduction, lipid lowering, triglyceride lowering, improved blood sugars, reduced blood pressure, improved mood states and a feeling of well being."

Reviewed by: Harry Pino, Ph.D.