Iranian Journal of

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Background: The aim of this study was to compare responses of Visfatin and insulin resistance index to various resistance exercise protocols. Methods: Ten healthy male subjects performed three resistance exercise protocols including maximal strength (three sets of 5 repetition at 85% of 1-RM with 3-min rest between sets), hyperthrophy (three sets of 10 repetition at 70% of 1-RM with 2-min rest between sets) and strength-endurance (three sets of 15 repetition at 55% of 1-RM with 1-min rest between sets) in three separate sessions. Two blood samples were taken before and after resistance exercise protocol. Responses to different resistance exercise protocols were compared by using repeated measures of ANOVA (3×2). Results: Irrespective of resistance exercise protocol, results showed that plasma visfatin reduced significantly (P<0.05) in response to resistance exercise. Between group comparisons revealed that reductions in visfatin concentration in response to strength-endurance and hypertrophy protocols were significantly higher than maximal strength protocol (P<0.05). Analysis showed that not only glucose, insulin and insulin resistance index did not change in response to resistance exercise significantly, but also there was no significant difference among the responses to different resistance exercise protocols (P>0.05). In addition, there was no significant relationship between changes in visfatin and other parameters (P>0.05). Conclusion: It could be concluded that performing strength-endurance and hypertrophy protocols that cause reductions in visfatin, possibly due to changes in growth hormone during these protocols, could be beneficial in reducing the hyperinsulinemia.

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Background: The purpose of this study was the investigation effect of gender on plasma glucose, insulin and insulin resistance index in response to acute endurance activity and subsequent recovery periods in healthy individuals.

Methods: Eight females and seven males 20-30 years old (females 22.37±1.50 and men 23.42±1.27 years old, female weight 55.50±8.14 men and 79.85±15.16 kg, women height 160.12 ± 4.18 men and 179.71±6.57 cm) voluntarily participated in this study. Subjects performed two control activities during two consecutive weeks. The implementation of the sessions was randomly determined for each subject. Exercise program consisted of 45 min acute endurance at 75% of maximum heart rate on the treadmill and subsequently the subject was in a sitting position for one clock recovery. Four blood samples (6 ml) before and immediately after exercise, as well as 1 and 24 hours after the activity was collected. Two-way analysis of variance for data analysis was used.

Results: Regardless of gender, effects of activity and recovery on plasma insulin and insulin resistance index was significant (p <0.05) but not significant for glucose. Also when the data were corrected by changes in plasma volume, similar results were observed for insulin. Although changes of all factors (glucose, insulin, and insulin resistance) in response to activity session of acute exercise endurance was higher in men than in woman, gender has not significant effect on factors.

Conclusion: acute endurance activity and recovery induce change in insulin resistance index but these changes were not related to gender.

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Background: Prevalence of obesity and overweight in women increases the possibility of metabolic syndrome and diabetes. Based on the variety of the effects of different type of exercise and the differences in the upper and lower body muscle volume involved in the exercise, the effects of high intensity interval exercise with arm and leg ergometer on metabolism and insulin resistance might be different. The aim of this study was to compare the effect of upper and lower body interval exercise on carbohydrate metabolism and insulin resistance in obese women.
Methods: Twelve obese and overweight women (body mass index, 31.1±5.5 kg/m²) performed two interval exercise trials of 30-min on arm and leg ergometer with one week intervening. Interval exercise included 5 sets of 6 min in which 2- min activity at 85% VO_2max and 4 min active rest at 45% VO_2max was performed. Two blood samples were taken before and immediately after exercise for measuring glucose and insulin. VO₂ and VCO_2m were collected during exercise and used to calculate the amount of carbohydrate oxidation.
Result: Although interval exercise reduced the insulin concentration, responses of insulin to upper and lower body exercises were not significantly different (P>0.05). Glucose level reduced following interval exercise, and this reduction was significantly (P<0.05) higher following lower body interval exercise than upper body exercise. Similarly the reductions in HOMA-IR were significantly (P<0.05) higher following lower body interval exercise than upper body exercise. Interval exercise resulted in increases in oxidation of carbohydrate, though; responses to upper and lower exercises were not significantly different.
Conclusion: It could be concluded that interval exercise in obese women leads to changes in carbohydrate metabolism and insulin resistance, and that the changes in insulin resistance are related to type of exercise (upper and lower body), though carbohydrate oxidation is not.