The Relation between Concentric and Eccentric EXERCISE and the Carbohydrate Metabolism in Healthy Individuals

Abstract

The purpose of the present study was to determine the response of glucose (G), insulin (In) and insulin like growth factor (IGF)-I to eccentric (ECC) vs. concentric (CON) resistance exercise in healthy trained and untrained subjects. Venous blood samples were drawn before and immediately after the test, and during 1-hour recovery for the determinations of hormonal and somatomedin concentrations. As compared to resting values, the maximal eccentric (ECC) resistance exercise test caused a significant decrease in G level (p<0.05). Significant differences were observed in post-exercise G level during ECC exercise (p<0.05). Different types of muscle contractions (ECC vs. CON) and resistance training had a significant effect on serum IGF-I concentration at maximal exercise intensity. A significant increase in IGF-I concentration was observed in response to eccentric muscle contraction in trained subjects compared to the control. Conclusions: These results seem to have demonstrated that in healthy subjects increased serum IGF-I concentration might be responsible for better glucose transport during resistance exercise, and this predominantly in eccentric muscle contraction.