ABSTRACT
To investigate the effect of heavy resistance exercise on IGF-1 system, 19 healthy trained men and 15 healthy untrained men volunteered to participate in this study. The subjects were randomly divided into experimental and control groups. Subjects of experimental groups were forced to perform a heavy resistance exercise with the intensity of 70-80% of 1RM in selected movements. The blood samples were taken from all subjects four times; before (T1), immediately after (T2), 5 (T3), and 8 (T4) hours after exercise. Analysis of data showed that a session of heavy resistance exercise induced significant increase in GH at T2 (P < 0.05) and a significant decrease in insulin at T4 (P < 0.05) and a significant decrease in IGFBP3 at T4 (P < 0.05) in trained group. In untrained group, no significant change in any of the variables was observed. However, the procedure of response in variables was almost similar in two experimental groups. Although, the exercise did not appreciably affect IGF-1 levels, it decreased in all groups at length of time after exercise. In addition, the exercise did not have any notable effect on IGFBP1 levels over time. In conclusion, the findings of this study indicate that the intense resistance exercise can lead to changes in blood concentrations of IGF-1 system components which are observable in blood circulation over time and the amounts of changes depend on subjects' fitness levels and exercise variables.
Subject(s)
Growth Hormone/blood , Insulin-Like Growth Factor Binding Protein 1/blood , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/metabolism , Insulin/blood , Physical Exertion/physiology , Resistance Training , Adult , Body Mass Index , Humans , Life Style , Male , Physical Fitness/physiology , Surveys and Questionnaires , Time FactorsABSTRACT
We designed this study, to investigate the predicting effect of a single resistance exercise session on serum level of RBP4 and adiponectin in trained and untrained subjects and to evaluate whether regular training may affect the response of these adipokines to exercise. Thirty four healthy young male students including 19 trained and 15 untrained participated in this study; each group was then randomly assigned to intervention and control groups. The exercise session prolonged 120 minutes intensive resistance program at 70%-80% of 1RM. The blood samples were collected just before the start of training program and 4 hours post exercise to evaluate concentration of adiponectin, RBP4 and CRP as well as other metabolic markers. The serum level of adiponectin, RBP4 and CRP was not significantly different between trained and untrained groups at baseline. More over four hours post exercise adipokines concentration and CRP didn't differ between groups. Adjusted regression model showed, basal adiponectin (ß=0.59, p=<0.001) and HDL cholesterol (ß=0.28, p=0.09) were the main predictors of post exercise adiponectin concentration. In addition, the basic level of RBP4 appeared to be the only predictor of after exercise RBP4 concentration (ß=0.46, p=0.02). Neither one session of high intensity resistance exercise nor long term training had predicting effect on post exercise adiponectin and RBP4 concentration in healthy young men. In the other hand, the beneficial effect of acute resistance exercise training may not be reflected by changes in adiponectin, RBP4 and CRP concentration in healthy young individual no matter they trained or untrained.
