Insulin resistance, often accompanied by obesity, plays a major role in the development of type 2 diabetes. This phenomenon may be related with the fact that American adolescents are now becoming less physically active in early puberty, explaining the largely pubertal and post-pubertal onset of type 2 diabetes in adolescence. Although regular physical activity has been suggested to attenuate obesity and prevent type 2 diabetes in high-risk children and adolescents, the magnitude of exercise training-induced improvement in the risk factors for type 2 diabetes has been only recently studied in adults and studied very little in pediatric populations. It is clear that exercise, diet, and genetics all contribute to the development of type 2 diabetes in children. However, the few studies that have been done to dissect the relative contributions of these three risk factors have generally used only lipid profiles as the end point. There have been a number of recent advances in our understanding of the molecular basis of type 2 diabetes, particularly, with regards to insulin regulatory pathways modulated by exercise within muscle tissue.

Insulin resistance, often accompanied by obesity, plays a major role in the development of type 2 diabetes. This phenomenon may be related with the fact that American adolescents are now becoming less physically active in early puberty, explaining the largely pubertal and post-pubertal onset of type 2 diabetes in adolescence. Although regular physical activity has been suggested to attenuate obesity and prevent type 2 diabetes in high-risk children and adolescents, the magnitude of exercise training-induced improvement in the risk factors for type 2 diabetes has been only recently studied in adults and studied very little in pediatric populations. It is clear that exercise, diet, and genetics all contribute to the development of type 2 diabetes in children. However, the few studies that have been done to dissect the relative contributions of these three risk factors have generally used only lipid profiles as the end point. There have been a number of recent advances in our understanding of the molecular basis of type 2 diabetes, particularly, with regards to insulin regulatory pathways modulated by exercise within muscle tissue.

• INCLUSION CRITERIA:

To be included in this study, subjects must meet the following conditions:

Sedentary (regular aerobic exercise less than or equal to 2 times/wk and less than 20 min/session): nonsmoker; impaired glucose tolerance (fasting plasma glucose greater than or equal to 100 mg/dl but less than 126 mg/dl or/and 2 hour plasma glucose greater than or equal to 140 mg/dl but less than 200 MG/dl; BMI-for-age is 95% or greater.

EXCLUSION CRITERIA:

Not pregnant; and not have any other medical condition that would preclude regular exercise.

If taking medication known to affect metabolism.

History of chronic illness known to affect metabolism.