Effects of Exercise-Induced Muscles Damage on Regulation of Glucose Metabolism and Cytokines Regulation

Abstract

This study was aimed to investigate the effects of exercise-induced muscle damage on the changes in blood glucose, serum insulin, creatine kinase (CK) and cytokines during five days post recovery period. Ten male elite swimmers of a school team were recruited as subjects in this study. All the subjects were under detraining for ten days, and the blood samples were collected before the single training as baseline levels. Subjects were asked to be trained under a designed program with an experienced trainer and the blood samples were collected after training and also one day, three days and five days after training. Blood glucose metabolism, bio-indicators such as CK, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were analyzed as the indexes in post recovery period. One-way ANOVA has been used to determine the significance between baseline and different recovery time periods. In the analysis of glucose metabolism test, fasting blood glucose, serum insulin, and HOMAIR which were seen as insulin resistance indexes were significantly higher (p＜.05) on the first day of the post recovery period. But the insulin resistance status was not continuously found in the third and fifth day after training. Meanwhile, the CK levels were truly higher (p＜.05) from the first day to the fifth day of recovery period. The pro-inflammatory cytokine IL-6 known as energy sensor in muscle was elevated significantly (p＜.05) from the first day to the end of the recovery period, and TNF-α was increased significantly (p＜.05) as IL-6 after single bout of high intensity training. These results conclude that acute intense training-induced muscle damage causes a short term of insulin resistance from exhausting of muscle glycogen. Monitoring of cytokines such as IL-6 and TNF-α could be biomarkers that indicated the recovery status of during the post training period. In the beginning of the muscle damage, high quality protein intakes should promote the muscle repairing, and then high carbohydrate consumption could help with glycogen replenish in the recovery period.