High-Intensity Physical Training Improves Cardiovascular Fitness in Obese Adolescents

After school lifestyle education and physical training programs can benefit obese children and adolescents by altering their body compositions and providing primary prevention of cardiovascular disease. In a study in the American Journal of Clinical Nutrition of obese adolescents, Gutin et al. investigated whether lifestyle education by itself, or in combination with moderate- or with high-intensity physical training, provided the most significant advantages in the fitness and body composition of juveniles.

The study included eighty 13-16 year old obese boys and girls of all ethnicities who were randomly assigned to receive either after school lifestyle education classes (LSE) by themselves, LSE combined with moderate-intensity physical training, or LSE combined with high-intensity physical training over 8 months. The LSE sessions included principles of behavior modification, information about nutrition and physical activity, and problem solving and coping skills. Based on data obtained from dietary recall records and the treadmill tests, an exercise prescription was developed for each teenager enrolled in a physical training program. Classes were offered 5 days per week, during which most of the teenagers were transported to and from physical training by van from their school. Class sizes were kept small enough so that physical training could be closely supervised.

According to a treadmill test, adolescents enrolled in the LSE plus high-intensity physical training program improved their cardiovascular fitness profiles significantly more than did those in the LSE program alone; however, the moderate-intensity physical training group was not significantly different from either of the other groups. Body composition changes such as declines in abdominal fat and percentage body fat were also significantly greater in the high-intensity physical training group, whereas body fat percentage increased slightly in the group who received LSE alone. Bone mineral density also increased significantly in the LSE plus physical training group, which suggests that exercise has a favorable effect on bone development in growing adolescents. However, the differences between high-intensity and moderate-intensity physical training were less significant in modifying body composition in these obese adolescents.

The authors suggest that obese teenagers be advised to exercise as vigorously as they can sustain to achieve improvements in cardiovascular fitness.

Additional Sources: Gutin, Bernard et al. Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents. Am J Clin Nutr 2002;75:818-26.

This release is provided by The American Society for Clinical Nutrition to provide current information on nutrition-related research. This information should not be construed as medical advice. If you have a medical concern, consult your doctor. To see the complete text of this article, please go to: http://www.faseb.org/ajcn/May/12546-Gutin.pdf

Source: American Journal of Clinical Nutrition