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 this study was to compare the effect of different types of isokinetic contractions on hemodynamic parameters in men. Ten healthy male subjects [age, 26.1 +/- 3.4 years] in three separate sessions performed three exercise protocols included Concentric/Concentric [C/C], Eccentric/Eccentric [E/E] and Concentric/Eccentric [C/E] contractions [flexion and extension] in the knee joint. In each session subjects performed 4 sets, 10 repetitions, at the speed of 60 degree per second. Hemodynamic parameters [heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and rate of pressure product] were measured before exercise, immediately after exercise and after 30 min recovery. Data were analyzed using two- way repeated measures of ANOVA. Statistical analysis of data showed significant increases in heart rate, systolic blood pressure [P<0.001], mean arterial blood pressure [P=0.053] and rate of pressure product [P<0.001] during exercise and significant reductions in these parameters in recovery period. Rate of perceived exertion [RPE] was significantly different among the contraction protocols [F[2,34]=15.5] and post-hoc test showed that RPE was lower in E/E protocol than the other two protocols. Hemodynamic parameters change in response to different muscular contractions, though these changes are not related to contraction type
Subject(s)
Humans , Male , Hemodynamics , Blood Pressure , Exercise , Knee Joint , Heart Rate , Analysis of VarianceABSTRACT
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
Reports in the literature on the menstruation cycle and its effect on exercise performance are contradictory, while consumption of nutrient supplements by women aiming at enhancing performance is invreasing. The purpose of this study was to investigate the effect of L-carnitine supplementation in the follicular and luteal phases of the menstrual cycle on the aerobic capacity and metabolic responses and performance after exhausted exercise in active women. The study design was a double-blind cross-sectional trial. Twenty-six active volunteer college girl-students, 22.8 +/- 3.0 years old, with a regular menstrual cycle with the folowing anthropometric measurements were selected: weight, 56.6 +/- 6.0 Kg; height, 163.3 +/- 4.0 cm; BMI, 20.8 +/- 1.2 kg/m2. They were invited to come to our laboratory 3-9 days [i.e., in the follicular phase] and 18-25 days [i.e., in the luteal phase] after bleeding, at 2 consecutive months. They took either L-carnitine or placebo [40 mg/Kg body weight] capsules 2 hours before the Brunce test. The statistical tests used for data analysis were the one-way ANOVA with repeated measurement for parametric, and the Freidman test for non-parametric, data. The maximal oxygen consumption and time to exhaustion in both follicular and luteal phases increased significantly with L-carnitine supplementation by 5.5% and 6.7% [as compared to placebo], respectively. Also, L-carnitine supplementation in both phases led to a statistically significant decrease in blood lactate accumulation [F3,66 = 5.235, P =0.003]; the magnitude of reduction in the follicular phase was 28.2% higher than in the luteal phase. On the other hand, the respiratory ventilation in the luteal phase increased significantly with L-carnitine supplementation [15% higher compared to the follicular phase]. L-carnitine supplementation in the follicular phase, when estrogen is at its minimal level, can help decrease a reduction in VO2max and excrcise performance. The increased serum L-carnitine level may cause an increase in beta-oxidation and, thereby, increase VO2max and enhance performance