[ relationship between cardiovascular fitness and physical activity with obesity and changes in their pattern among 12-16 year-old boys]

This study aimed at determining the association between cardiovascular fitness and physical activity with obesity and changes in their patterns among 12-16 year-old boys. In this cross-sectional study, 275 boy students, 12-16 year-old; from Bardaskan city were investigated. Subjects were selected via random sampling. Underweight, overweight and obesity status were evaluated based on the 5[th], 85[th] and 95[th] percentiles of body mass index [BMI] for age and sex based on the United States' Center for Disease Control [CDC 2000] standards. Physical activity levels were estimated by the Physical Activity Questionnaire for Older Children [PAQ-C]. Cardiovascular fitness [VO2max] was assessed by a 20 m shuttle run test. Overall prevalence's of underweight, overweight and obesity among subjects were 3.6%, 10.5% and 4.7% respectively. There was significant positive correlation between physical activity level and cardiovascular fitness. Cardiovascular fitness and physical activity levels decreased significantly with aging. The overweight and obesity groups had lower levels of cardiovascular fitness than the normal and underweight groups. There was no statistically significant difference between the overweight-obese and the non overweight groups in physical activity levels. Moreover, There was a significant negative correlation between physical activity and cardiovascular fitness levels and subjects' BMIs. Considering the in adequate levels of cardiovascular fitness and physical activity in overweight and obese boys, programs increasing physical activity [endurance exercise], and diet and weight control are recommended for these groups

[Effect of short-term garlic extract supplementation on oxidative stress indices during rest and induced-exercise exhaustion in male soccer players]

The present study aims to investigate the effects of exhaustive running and different doses of short-term garlic supplementation on total antioxidant capacity [TAC] and Malondialdehyde [MDA] in during rest and exercise induced exhaustion in male soccer players. Thirty male football players [Average age: 20.8 +/- 1.45 y; maximum oxygen intake 67.2 +/- 5.4 ml/kg/min and body mass index 21.5 +/- 1.34 kg/m2] were divided randomly into three homogenous groups, the placebo group and the 2 garlic supplementation groups given two dosages [1200 and 2400 mg/day]. The first and second blood samples were taken in the basic state and after the Shuttle Run test and the third and fourth samples were taken after supplementation, in the basic state and after test. The parameters were then analyzed using one-way ANOVA, with a significance level of a=0.05. Exhaustive running significantly decreased TAC and increased MDA level in the blood serum of male football players. On the other hand, garlic supplementation increased TAC [P<0.01] and decreased MDA [P<0.01] in the basic state. Moreover, supplementation hindered significant increase in the level of MDA [P<0.05] in male football players after the test but it failed to stop the decrease in TAC [P<0.05] level. Furthermore, the decrease of TAC level in supplementation group was significantly [P<0.05] less than in the placebo group. Short-term garlic extract supplementation may increase TAC and MDA in male football players in the basic state and hinder the fall in the total antioxidant capacity and oxidative stress after vigorous exercises. On the other hand, neither dosages of 1200 nor 2400 mg/day of garlic extract showed any effects on TAC or MDA in the groups of players investigated

[Fat oxidation and energy expenditure at different intensities of exercise during running and cycling in obese adolescent boys]

Running and cycling are two modalities of exercise commonly used to promote fat oxidation in weight loss programs for obese people. In order to design appropriate training programs, the objective of the present study was to compare fat oxidation and energy expenditure at different intensities of exercise during running and cycling in obese adolescent boys. Eleven healthy obese adolescent boys [mean age 13 +/- 1.2 years, mean weight 73.1 +/- 7.6 kg, and body mass index 27.5 +/- 2.5 kg/m2] voluntarily participated in this study. Subjects performed 2 incremental graded exercise tests on a cycle ergometer and a motorized treadmill. Heart rate, mean oxygen consumption and carbon dioxide generation during the last two minutes of each level of test were measured and respiratory exchange ratio was calculated. Energy expenditure and fat and carbohydrate oxidation rates were calculated at different intensity levels. At comparable and similar heart rates, the fat oxidation rate was significantly higher during running, compared to cycling over a wide range of intensities [p<0.05], except at intensities of 20w and 170w, as was the total energy expenditure, compared to cycling [266 +/- 43 vs237 +/- 39 kJ/min] [p<0.05]. Carbohydrate oxidation was, however, significantly higher during cycling compared to running, at intensities of 45w, 70w and 95w. It is concluded that for obese adolescents, in order to lose weight and reduce body fat mass [increased energy expenditure and promoted fat oxidation in a certain level of cardio-vascular responses], moderate intensity of running would be more effective than cycling

Influence of physical fitness training on some immune system markers in athletic students

Purpose: Many researches have been conducted on the relationship between exercise and immune system but few have focused on the effect of physical fitness programs on the system. Therefore, this study was carried out to investigate the influence of a 12-week program on such markers as IgG, neutrophils, lymphocytes and serum cortisol at rest in athletic students

Method and Materials: In this study, 11 athletic students [age 22.02 +/- 2 years, weight 61.2 +/- 5.3 Kg and stature 174 +/- 4.45 cm] voluntarily participated as the experimental group and 11 nonathletic students [age 22.5 +/- 2.5 years, weight 62.1 +/- 6.2 Kg and stature 173 +/- 3.5 cm] voluntarily participated as the control group. Blood samples were collected at rest from athletic students before physical fitness training. The program included resistance, speed and endurance training with intensity 65-100% maximal HR. After 12 weeks, blood samples were collected from both groups

Results: Dependent and independent t-test analysis indicated that physical fitness training did not significantly change serum IgG and cortisol at rest [p>0.81 and p> 0.65 respectively]. It significantly decreased neutrophils and increased lymphocytes [p<0.001 and p<0.012 respectively]. Athletic and non-athletic students were not different in these markers

Conclusion: Although neutrophils decreased due to the training program but the range of variation was normal. In general, it can be concluded that physical fitness training does not weaken the immune system in athletic students