Jun 27, 2002 (NewsRx.com & NewsRx.net) - Overweight teens needn't develop Olympian-in-training exercise routines to improve their fitness and reduce their weight; exercise - even at moderate exertion - produces a wealth of health benefits, according to a Medical College of Georgia (MCG) researcher.
Three key indicators of wellness and fitness improved when obese adolescents participated in exercise routines, even when the exercise was moderate, according to Dr. Bernard Gutin, an MCG professor of pediatrics and physiology. The results of his study, funded by the National Heart, Lung and Blood Institute, were published in the American Journal of Clinical Nutrition.
For the study, 80 teens ages 13-16 were randomly placed in one of three groups. One group participated in a high-intensity exercise class five times a week for eight months and received instruction in healthy living. A second group also received the instruction and participated in a moderate-intensity exercise class for the same time period. A third group received only the instruction and did not participate in an exercise program.
The exercises were similar for both exercise groups, including work on treadmills, stationary bikes, mini-trampolines and step benches. But the moderate-intensity group was directed to exert less effort during a 40-minute period than the high-intensity group during a 30-minute period, achieving a lower average heart rate than the high-intensity group.
Before the exercise programs began, Gutin and his colleagues measured all of the participants' total body composition (percentage of fat, muscle and bone), cardiovascular fitness as measured by a treadmill test and visceral adipose tissue (abdominal fat). "It's been shown that total fat is unhealthy and [abdominal fat] is particularly unhealthy," Gutin said.
Both can lead to conditions such as cardiovascular disease and adult-onset diabetes, he noted. In addition, bone density - even in adolescence - can predict future health problems, such as osteoporosis.
The researchers repeated their measurements of these key indicators at the end of the eight-month exercise programs and found that members of both exercise groups were substantially healthier and more fit. The measurements of the group that received only the lifestyle instruction were unchanged.
"The data didn't show clearly that high-intensity exercise was more effective than moderate-intensity exercise for improving body composition, but the more vigorous exercise did seem to have a more beneficial effect on cardiovascular fitness," Gutin said.
Such findings can help physical education teachers and other professionals fine-tune programs to optimize teen compliance, Gutin said. Any program that will get teens moving, he said, is a worthy effort with potentially long-range health implications (Am J Clin Nutr, 2002;75(5)).
"There is good reason to believe we should try to enhance fitness at a young age," he said. "The [disease] processes that ultimately result in heart disease, adult-onset diabetes and osteoporosis begin in childhood. The study suggests that a structured after-school exercise program combined with lifestyle education is a good way to prevent further deterioration as teens grow into adulthood." This article was prepared by Obesity, Fitness & Wellness Week editors from staff and other reports.
