The comparison between effects of circuit and hypertrophy resistance exercise on fat and carbohydrate metabolism during endurance exercise in overweight men

the aim of the present study was to compare the effects of circuit and hypertrophy resistance exercise protocols with equal volumes on fat and carbohydrate metabolism during endurance exercise in overweight men. Ten overweight men (Mean±SD, age, 28.8±4.8 yr; BMI, 28.2±1.4 kg/m2) performed three exercise trials including 1) endurance exercise (E), 2) circuit resistance exercise followed by endurance exercise (CRE), and 3) hypertrophy resistance exercise followed by endurance exercise (HRE). The exercise sessions were randomly performed with one week intervening. The endurance exercise encompassed the 30 min of cycling at 60% of VO2max. Circuit weight training included 3 set of 14 repetitions at 50% of one-repetition maximum for six exercise, whereas hypertrophy protocol included 3 sets of 14 repetitions at 50% of 1 RM. Respiratory gases were collected before, during and 30 minutes after endurance exercise for calculating fat and carbohydrate metabolism. Three blood samples were taken before, during and 30 minutes after endurance exercise and were analysed for glucose, insulin, free fatty acid, glycerol, malonyl coA, and GLUT-4. Plasma glycerol concentration before, during and after recovery in CRE session were higher than E and HRE trials and that in HRE trial were higher than E trial (P<0.001). Plasma glucose concentration during endurance exercise in HRE trial was significantly reduced more than CRE and E trials (P<0.05). Carbohydrate oxidation rate during endurance exercise was significantly higher than CRE and HRE trials (P<0.05). However, there were no significant differences among the three exercise trials for fat oxidation, insulin, free fatty acid, glycerol, malonyl coA, glut-4, and insulin (P>0.05). Based on the findings of present study, it could be concluded that circuit resistance exercise induces higher lipolysis during endurance exercise than hyperthrophy protocol; in spite of the exercise volume being equal, but fat and carbohydrate oxidation during endurance exercise are not affected by type of resistance exercise.