THE QUESTION: Exercise helps combat the cluster of risk factors known as metabolic syndrome, which makes people far more susceptible to heart problems. But does the intensity of exercise make a difference?

THE QUESTION: Exercise helps combat the cluster of risk factors known as metabolic syndrome, which makes people far more susceptible to heart problems. But does the intensity of exercise make a difference?

THIS STUDY randomly assigned 32 people (average age, 52) with metabolic syndrome to do either vigorous or moderate exercise on a treadmill for 40 minutes three times a week, or to do no treadmill exercise. Participants wore heart-rate monitors while exercising. After four months, both exercise groups had lost weight (5 to 8 pounds, on average) and inches at the waist (an average of 2). About 46 percent of the vigorous exercisers and 37 percent of the moderate exercisers were no longer diagnosed with metabolic syndrome; in the no-exercise group, everyone continued to meet the diagnostic standards for metabolic syndrome.

WHO MAY BE AFFECTED? People who have or are at risk for developing metabolic syndrome, which is based on having at least three of the five conditions that raise the risk for heart disease, diabetes and stroke: high blood pressure, high blood sugar levels, higher than normal levels of triglycerides (a fat) in the blood, below-normal levels of high-density lipoprotein cholesterol and too much fat around the waist.

CAVEATS: The number of participants was small. Anyone considering treadmill exercise should first consult a doctor.

FIND THIS STUDY: July 8 issue of Circulation: Journal of the American Heart Association.

LEARN MORE ABOUT metabolic syndrome at www.nhlbi.nih.gov/health and www.familydoctor.org.

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.