ABSTRACT
Introduction: The aim of this study was to investigate the effects of upper and lower body activities on fat and carbohydrate oxidation in the elderly
Materials and Methods: Nine elderly men [age, 66.1+/-3.91y; body mass index, 25.09+/-2 kg/m[2]] participated voluntarily in this study. After determining the upper and lower body VO[2]max, subjects performed two interval exercise trials with one week interval. Interval exercise included 4 stages of 5-min activity respectively, at an intensity of 55, 60, 65, and 70% VO[2]max on hand ergometer and bicycle ergometer. Each stage was followed by 2.5 min of activity performed at 25, 30, 35, and 40% VO[2]max. Respiratory gases were collected before exercise at the 1[st] 10-min, 2[nd] 10-min, 3[rd] 10-min and 30-min recovery and used to calculate fat and carbohydrate oxidation
Results: Changes in fat oxidation during interval exercise with cycle ergometer was significantly [P<0.05] higher than arm-cranking. However, changes in carbohydrate oxidation during interval exercise with cycle ergometer and arm-cranking were significantly [P=0.009] different. Post-hoc analysis showed that carbohydrate oxidation during 30-min recovery was higher in the cycle ergometer trial than arm-cranking
Conclusion: Based on findings, there is more increase in fat and carbohydrate oxidation during lower body interval exercise in elderly individuals, compared to upper body exercise, and this type of exercise is recommended for better fat oxidation
ABSTRACT
The purpose of the present study was to investigate the combined effects of endurance training and fasting during Ramadan on fat and carbohydrate metabolism. Twenty four healthy men [age, 25.4 +/- 2.3 years] were randomly allocated to two groups of fasting [F, n=12] and fasting + endurance training [F+ET, n=12]. The study protocol for the F group included 10 and the F+ET group had 12 subjects. The fasting group only fasted during Ramadan, whereas the F+ET group, in addition to fasting, performed three sessions of endurance training on the treadmill after Iftar. Antropometric indices, blood samples and dietary intakes were documented the beginning of Ramadan and after the first week and at the end of Ramadan. Weight and body mass index did not change significantly during Ramadan in either group [P>0.05], but the body fat percentage reduced significantly [P<0.05] during Ramadan in both groups. Fat oxidation, carbohydrate oxidation, insulin, glucose, glycerol, and non-esterified free fatty acid changed in the first week of Ramadan, more pronouncedly in F+ET group, whereas in the F group these changes occurred more during the second half of the Ramadan, though the changes did not differ significantly between the two groups. Combining Ramadan fasting and exercise training affects the trend of changes in fat and carbohydrate oxidation during Ramadan. Generally however the effects of two protocols were similar and adding the endurance training to fasting did not induce more changes than fasting perse
ABSTRACT
This study examined the effects of circuit resistance exercise 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; vo2max, 23.3 +/- 3.7 ml/kg/min] performed two types of exercise regimens: 1] Endurance exercise [E], and 2] Circuit resistance exercise, followed by endurance exercise [RE]. Circuit resistance exercise consisted of six stations, each with three circuits at 50% of 1-RM [one repetition maximum], and a total exercise time of 21 min. Endurance exercise consisted cycle ergometer exercise at 60% of the maximal oxygen uptake for 30 min. Expired gases at rest, before and during endurance exercise were measured for calculating fat and carbohydrate oxidation. Venous blood samples were taken at rest, before and immediately after endurance exercise. Blood samples were analyzed for glucose, nonestrified fatty acids [NEFA], malonyl COA [MCOA], glycerol and insulin. Plasma glycerol concentrations during endurance exercise increased 53% in RE vs. 46% in the E group [P<0.001]. Concentration of plasma glucose before endurance exercise was higher in RE than in the E group [P<0.001]. In RE exercise, although fat oxidation through the 30-min endurance exercise [mean value] was greater than in the E regimen, there was no significant difference between the two groups [P>0.05]. Also, no significant difference was observed in the NEFA, MCOA, insulin, carbohydrate oxidation responses [P>0.05]. Lipolysis during the submaximal exercise is enhanced by prior circuit resistance exercise in overweight men.
ABSTRACT
The purpose of this study was to determine the effects of L-carnitinesupplementation on carbohydrate [CHO] and fat metabolism after resistance exercise. In this investigation, using a double blind, randomized, crossover, repeated measure design [1 wk washout], 10 healthy resistance-trained men [Mean +/- SD: age, 24.03 +/- 2.00 yr; mass, 72.26 +/- 5.31 kg; height, 173.90 +/- 5.02 cm] consumed 2 g placebo or LC supplement daily for one week and then performed 6 exercises of a resistance exercise protocol. Each workout was performed for 3 sets of 12 repetitions with 55% 1RM and rest periods were kept to 60 s between all sets and workout. Expired gases were measured for calculating CHO and fat oxidation. Venous blood samples were obtained before and after supplementation, immediately after resistance exercise and after the 1[st] and 24[th] hour after resistance exercise. Samples were analyzed for markers of glucose, NEFA, glycerol and insulin. Also L-carnitine plasma concentrations were measured, before and after supplementation. The results of this study suggest that plasma carnitine concentrations increased 14% [p 0.05]. Increased plasma insulin concentrations with L-carnitine and placebo after resistance exercise attenuated result in attenuate fat oxidation in this study