[Effect of gender and physical activity on serum vascular endothelial growth factor at rest and response to submaximal exercise]

Although the effects of exercise on angiogenic factors is a topic that has attracted the attention of many researchers worldwide, the possible impacts of gender and physical activity on the rate of angiogenic factors at rest and response of acute exercise have not been investigated so far and which is why we conducted this research. Sixteen women [8 active, 8 sedentary] and 16 men [8 active, 8 sedentary] participated in this study. Three days after determination of V02max, they exercised for 1 h at 70% V02 max. Serum was collected from the vein at rest and at 0 and 2 h, post exercise. Serum vascular endothelial growth factor [VEGF] was measured by ELISA kits. Serum levels of VEGF decreased immediately after exercise in groups, a change that was temporary and transient. At rest, no difference between serum VEGF of groups was seen. On the other hand, changes in VEGF levels in response to exercise between groups were not significant. Acute submaximal exercise decreases the main angiogenic factor involved in development of capillary network. Gender and physical activity do not affect serum levels of the vascular endothelial growth factor at rest or response of exercise

[ effects of L-carnitine supplementation in different phases of menstrual cycle on the metabolic responses after exhausted exercise in active women]

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

[ effects of acute L-carnitine supplementation on anaerobic threshold and lactate accumulation during an incremental exercise]

Appropriate nutrition is an essential prerequisite for effective improvement of athletic performance, conditioning, recovery from fatigue after exercise, and avoidance of injury. Nutritional supplements containing carbohydrates, proteins, vitamins, and minerals have been widely used in various sporting fields to provide a boost to the recommended daily allowance. The aim of this study was to investigate the effects of acute L-carnitine supplementation on anaerobic threshold and lactate accumulation during incremental exercise. The study was double-blind, randomized and crossover in design. The subjects were 12 randomly selected active male physical education students, 21.75 +/- 0.64 years old, with a mean body mass index [BMI] of 23.7 +/- 0.94, divided into 2 groups. They received orally either 2g of L-carnitine dissolved in 200 ml water plus 6 drops of lemon juice or a placebo [6 ml lemon juice dissolved in 200 ml water] 90 minutes before they began exercise on treadmill. They performed a modified protocol of Conconi test to exhaustion. Plasma lactate concentrations were recorded at rest and immediately after the test. One-way analysis of variance with repeated measurements was used for data analysis. The results showed that lactate accumulation immediately after exercise in the L-carnitine group [3.870 +/- 0.19] was significantly lower [p=0.000] than in the placebo [6.080 +/- 0.58] group. In addition, the intervention led to a higher increase [p=0.000] in the maximum oxygen consumption [50.54 +/- 1.48], as compared to the placebo group [45.16 +/- 1.51]. The data also showed that the length of time required to reach the anaerobic threshold was higher in the L-carnitin group [19.14 +/- 0.65, vs 16.00 +/- 0.28 for the placebo group]. There was no statistically significant difference between the 2 groups with regard to the respiratory exchange ratio. L-carnitine supplementation seems to cause a reduction in the blood lactate accumulation and delay anaerobic threshold in an incremental exercise, resulting in improved performance

[Effect of exercise with moderate intensity in the morning on some factors of immune systems in adults]

The purpose of this study was to determine changes in salivary immunoglobulin A concentrations [S-IgA] and cortisol levels and any relationship between them, in adults after eight weeks of moderately intense exercise in the morning. Thirty, healthy, adult men [aged 30-50 years] having a sedentary lifestyles, were randomly selected and assigned to either the control or the exercise group; their exercise program consisted of three sessions a week, for eight weeks. Each subject performed exercise at 06:00 a.m at 75% of maximum heart rate during the study, while controls continued their normal life style. Changes in fasting S-IgA concentrations and cortisol serum levels were monitored at the beginning and end of exercise at [0900] a.m following every session. Analysis of data was performed, using t-student test for comparing means of pre and post test. Pearsons correlation was used to determine any relationship between S-IgA concentration with cortisol concentration. The level of significance was chosen at P