If you haven’t heard the term before, the expanding obesity epidemic will soon make the phrase “metabolic syndrome” commonplace.

Metabolic syndrome is not a single disease, but a collection of risk factors that markedly increase an individual’s likelihood of developing cardiovascular disease, or having a heart attack. These major risk factors are obesity (particularly abdominal obesity), high blood pressure, and high cholesterol. Additionally, insulin resistance, diabetes and prediabetes are seen in the majority of people with metabolic syndrome. According to the International Diabetes Foundation fully one quarter of the world’s adult population has metabolic syndrome, and this confers a five-fold greater risk of developing type 2 diabetes.

The American Heart Association (AHA) reported the results of a small study on the effects of vigorous exercise on adults with metabolic syndrome. Thirty-two patients (average age of 52) were separated into three groups: one group did high-intensity aerobic-interval training, the second group did moderate-continuous-training, and the third group didn’t exercise. Results showed both exercise groups lost approximately the same amount of weight, but participants doing high-intensity aerobics had faster heart rates while exercising, and therefore absorbed and used more oxygen. Participants in this group also increased their ability to absorb oxygen by 35 percent compared to a much smaller 16 percent increase in oxygen absorption by the moderate exercise group. The vigorous exercise group also outperformed the moderate exercise group on several other key measures, such as blood pressure, HDL (good) cholesterol levels, and insulin sensitivity.

American Heart Association guidelines call for “30 minutes of moderate intensity on most days of the week,” but the researchers believe this recommendation may be too mild for those with metabolic syndrome.

A larger study would be needed before the AHA would officially change its exercise recommendations; however, in a written statement an AHA researcher and spokesperson conceded that “exercise performed at a vigorous intensity appears to convey greater cardioprotective benefits than exercise of a moderate intensity.”

For the AHA, the form of exercise offering the biggest boost in cardio benefits is not the only consideration. The association maintains that higher intensity exercise may lead to more physical injuries and cardiovascular complications, and ultimately to lower compliance with any work-out regimen. Their advice: if you’ve grown comfortable exercising at a moderate intensity consider including more challenging, vigorous routines to your workout, but only if you can do so safely.