INDIANAPOLIS -- Although any type of exercise is beneficial for health, high-intensity exercise is likely necessary to achieve significant improvements in body composition, according to a study released today in Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine, Indianapolis.

Arthur Weltman, Ph.D., and his team studied 27 middle-aged obese women with metabolic syndrome – a group of risk factors that includes abdominal obesity, unhealthy cholesterol levels, high blood pressure, elevated triglycerides and elevated fasting glucose. Seven of the women did not change their activity levels; 11 performed low-intensity (approximately 50-60 percent of maximum aerobic capacity) exercise five days per week; and nine performed low-intensity exercise two days and high-intensity exercise (approximately 75-80 percent of maximum aerobic capacity) three days per week.

The high-intensity group reduced total abdominal fat, subcutaneous abdominal fat, and visceral abdominal fat during the 16-week exercise period.

"Improving body composition can improve overall health and quality of life, and exercise-induced reductions in total and visceral abdominal fat can significantly lower the risk of chronic disease,” Weltman said. “For obese women entering the middle and later stages of life, reducing internal abdominal fat or preventing too much of it [from] forming is crucial. Exercise, especially vigorous exercise, may be the best way to do it. High-intensity exercise was prescribed based on each individual’s capabilities and allowed each woman to complete the exercise bouts. Often, people think they cannot engage in high-intensity exercise because they associate it with what athletes are able to do, not what is high-intensity for them. It varies from person to person."

ACSM and the American Heart Association recommend that healthy adults 18 to 65 years old need moderate-intensity aerobic physical activity for at least 30 minutes on five days each week or vigorous-intensity aerobic physical activity for at least 20 minutes on three days each week. However, overweight and obese persons may need up to 300 minutes of exercise per week to lose weight.