Exercise induced-changes in insulin-like growth factor 1 following fasting compared to glucose administration

Introduction: Carbohydrate supplement intake might change exercise induced-insulin-like growth factor 1 (IGF-1); however it is not well known. The purpose of the present study was to determine exercise induced-changes in IGF-1 following fasting compared to glucose administration. Material & Methods: Eleven non-athletes healthy men (aged: 21.0 ± 2.1 years; body mass index (BMI): 22.6 ± 3.3 kg/m2; mean ± SD) were participated in this study as the subject. At the first week, the subjects were consumed 1 g/kg body weight of glucose in 200 mL water 30 min prior to exercise (hyperglycemia condition) and subsequently walked on a treadmill at 50% of heart rate reserve (HRR) for 60 min. Glucose and IGF-1 levels were measured at baseline, immediately and 30 min after the exercise. After a week, the subjects were performed the same exercise after at least 14 h of fasting (hypoglycemia condition) and glucose and IGF-1 levels were measured at the same times of the first week. Results: The results showed that glucose levels were higher in hyperglycemia condition than hypoglycemia condition (P<0.05). Glucose level was decreased by 54.8% after the exercise but it was higher than the baseline until 30 min after the exercise (P<0.05). The results, also indicated that IGF-1 level had no significant changes after the exercise at both of hypo and hyperglycemia conditions and no significant differences were observed during blood sampling between hypo and hyperglycemia conditions. Conclusions: In conclusion, it seems that exercise in hypo or hyperglycemia conditions had no significant effect on IGF-1 levels.