SPORT AND BIOMOTOR SCIENCES
Year:2012 | Volume:2 | Issue:4|Papers Count:20

Introduction: According to the results of various studies, intermittent fasting during Ramadan could change the pattern of eating, sleeping and body pools. Hence, such alteration in behavioral patterns may possibly affect physiological responses to exercise, as well as athletes' reactions towards exercises and their athletic performance. Although physiological and metabolical responses to the physical activity in different dietary condition are known, the influence of fasting on various aspects of physical training still remains controversial. In this review, results of studies on probable effects of fasting and starvation on different aspects of exercise such as exhausting, physical capacity, weight and body composition, hormones and inflammation in athletes are discussed.Materials and Methods: Research articles related to Ramadan fasting and exercise were searched through the Internet using keywords such as "Ramadan", "Ramadan Fasting", "Islamic Fasting", Fasting in Ramadan", "Fasting along Exercise", "Physical Activity", "Physical Performance", Athletes and Training via PubMed database and some regional articles. All available articles (cross- sectional descriptive analytic, cohort, clinical trial and review articles) from 1984 until 2010 were reviewed.Results and Cnclusion: Ramadan fasting could just affect some aspects of exercise such as exhaustion. However, because of the athletic power reduction, it is not recommended to stop athletic practice during Ramadan. It is proposed that through some behavioral changes, in addition to good timing, athletes can continue training during Ramadan.

Introduction: There is an apparent paradox between the benefits of aerobic exercise and the potentialy deleterious effects of increased free radicals production and decreased antioxidant capacity of the body generated during exercise.Purpose: This study was carried out to assess the antioxidant capacity and oxidative stress status and lipoprotein profile in elite male cyclists.Material and methods: Total antioxidant capacity (TAC), malondialdehyde (MDA), conjugated dienes (CD) and Serum lipid and cholesterol profile (triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol and VLDL-cholesterol) were measured in 14 elite male cyclists and in equal number of age-matched non-athletes individuals in the age range of 18-21.Results: The results of an independent t-test showed that the athletes had significantly lower plasma values of MDA (p=0.04), total cholesterol (p=0.04), triglycerides (p=0.001), VLDL-cholesterol (p=0.001) and LDL/HDL ratio (p=0.04). Plasma level of TAC and CD were similar in both groups. Athlete showed decreased plasma level of LDL-cholesterol and increased level of HDL-cholesterol but there were not significant.Conclusion: It was found that regular cycling dose not lead to oxidative stress in athletes and they exhibit better lipid and lipoprotein profile than non-athletes.

Introduction: Coronary artery disease (CAD) is a leading cause of death in the developed and undeveloped world today. It is well established that increased total, LDL-cholesterol, and triacylglycerol concentrations, as well as decreased HDL-cholesterol concentrations, are strong independent predictors of CAD (1). Aerobic exercise is believed to reduce the risk of cardiovascular disease partially through increasing serum levels of high-density lipoprotein cholesterol (HDL-C). However, this effect varies considerably among exercise intervention studies. therefore, we considered the effect of 8 week endurance training of different duration son resting levels of HDL, HDL2, HDL3, TG, TC in plasma.Materials and methods: 50 Wistar male rats (6-8 week old) with mean weight of (189.98±6.589) grams were used. The rats were randomly divided into 5 groups (each group of 10 rats) including 3 experimental groups with different durations of 30, 60 and 90 minutes, abasic control group (in the cage) and basic group 2 (sham). The experimental groups were trained for 8 weeks, 5 days a week, each day with the speed of 20 m/min with different durations of 30, 60 and 90 minutes. 72 hours after the last session of training the rats were fed and killed (4 hours ago the food was taken from the rats' cage). Then, plasma was collected.The levels of HDL, HDL2, HDL3, LDL-C, TG and TC were measured by sedimentary and enzymatic methods. The data analysis was performed through statistical measures of ANOVA and LSD by using SPSS (version 16) software at significant levels of 5%.Results: No significant effect was found in levels of HDL, HDL2, HDL3-C, TG, LDL-C, VLDL-C, TC/HDL-C, LDL/HDL-c and HDL2-C/HDL3 between any of these groups after 8weeks endurance training (P=0.05). However, the results illustrated TC levels decreased significantly after 8 weeks training in 30 min and 60 min groups in contrast with control and sham groups (F=6/566, P<0.000).Conclusion: The present study showed that 8 week Endurance training with different durations has no significant effects on resting levels of HDL, HDL2, HDL3, TG, LDL-C, VLDL-C, TC/HDL-C, LDL/HDL-C and HDL2-C/HDL3. But TC levels decrease significantly after 8 weeks of endurance training.

Introduction: The purpose of this research was to study the effects of active recovery (slow swimming) and inactive recovery (sitting and massage) on level of blood lactate and heart rate in adult swimmers.Materials and methods: The statistical sample included 14 swimmers with the age range of 24.5±4.12 who were selected by chance. After accomplishment of three time maximum exercise activity (100 meters crawl swim) in specific times is three different days with an interval of two days (48 hours), the participants had a specific 12 minutes recovery program. The recovery program included a method of active recovery (slow swimming) and two methods of inactive recovery (sitting and massage). Then, the level of blood lactate and heart rate at an interval time before and after the maximum activity and the period of 12 minutes to recovery were measured. Wilkakson and Friedman Test was used for the analysis of the data using 0.05 level of significance.Results: Inactive recovery (sitting) does not have a significant effect on blood lactate level (P=0.064). Inactive recovery (sitting and massage) and active recovery (slow swimming) have a significant effect on heart rate (P=0.001, P=0.001, P=0.002). Inactive recovery (massage) and active recovery (slow swimming) have a significant effect on blood lactate level (P=0.001, P, 0.001). There are significant differences between different recovery methods with regard to blood lactate level and heart rate (P=0.03).Conclusion: Since slow swimming has more significant effect on the decrease of blood lactate and massage is more effective on decreasing heart rate, they are recommended to trainers and swimmers to be used for faster recovery programs.

Introduction: It is known that exercise affects carbohydrates, fats and proteins stores of the body. It is also likely that exercise, especially resistance exercise, affects nutrient intake and appetite. For this reason, the purpose of this study was to compare the effects of different intensity of resistance circuit exercises on the athlete’s appetite.Materials and Methods: After translation and modification of some of the questions, the standard questionnaires (VAS), (Flint, 2000), was used. The face validity of test was checked through questioning the experts of validity and the reliability of the test was ensured through the application of test-retest, reliability (Cronbach Alpha 0.63). The target population consisted of the entire male and female athlete students of the University of Guilan. The sample of the study included 45 males (3 groups of 15 persons) and 45 females (3 groups of 15 persons), with mean age of 21±1/85 and 21±24/2 years, height 176/02±5/99 and 161±4/93 cm, weight 68/36±9/29 and 55±6/89kg and body mass index 21/02±1/9 and 21/91±2/9 kg/m2 respectively. The participants randomly performed circuit resistance training with different intensity (50%, 65% and 80% one repetition maximum) in three separate sessions. The collected data were analyzed by KA, t-test, one-way ANOVA and Tukey test.Results: Results showed that exercise training with intensity of 50% Vs 65% 1RM significantly increased the appetite of male and female students (P<0.05). However, the differences in appetite between exercises with intensity of 65% Vs 80% 1RM and 50% Vs 80% 1RM in male and female were not significant (p>0/05).Conclusion: The results of the study show that circuit training with low intensity can be effective in reducing appetite as compared with high intensity. Therefore, it is recommended that such exercises, under the right practice conditions, could be used for preventing excessive appetite and high tendency for food consumption, especially in disciplines that require weight control.

Introduction: Physical fitness is one of the key factors that contribute to success of soccer players in competition. In addition, aspects such as body composition, maximal oxygen consumption and anaerobic power are of primary importance in success of soccer team.Thus, the aim of this study was to compare body composition, maximal oxygen consumption and anaerobic power changes in soccer players during competitions season.Materials and Methods: This was a semi experimental research with three experimental groups. 24 players of Pasargad Soccer Team including defenders (N=8), middles (N=8) and attackers (N=8) were voluntarily selected as the available statistical sample. Through the use of In-Body system, Astrand Treadmill Test and Running-based Anaerobic Sprint Test (RAST), body composition, maximal oxygen consumption and anaerobic power were measured in the beginning of competitions season (Aban month) and after the 15Th competition (Esfand month) during competitions season. Then, paired sample t-test (t-student) and ANOVA were used for the statistical analysis of the data at P=0.05 level of significance.Results: Defender, middle and attacker players showed a significant reduction in BMI 15 weeks after the start of competitions season. (p<0.05). Middle and attacker players showed a significant reduction in the percentage of body fat but there was no such reduction in defenders. Maximal oxygen consumption (VO2max) significantly increased in middle and attacker players and decreased significantly in defenders. (p<0.05). Further, defender and attacker players showed a significant increases in anaerobic power during competitions season (p<0.05).conclusion: It is likely that competition season could bring about changes in body composition profile, maximum oxygen consumption and anaerobic power changes in defenders, middle players and attackers of soccer. However, these changes depend on the posts of each soccer player as well as to the style of the team. The researchers of the study recommend the trainers to be aware of the intensity of such changes and enforce them in their training sessions during the season in order to prevent the power decrease of their players.

Introduction: The prevalence of cardiovascular mortality, in comparison with other diseases, is more common in patients with rheumatoid arthritis (RA). Drug therapy and insufficient physical activity in these patients may play an important role in cardiovascular disease (CVD) incidence. Hyperlipidemia is a primary CVD risk factor. The CVD potential risk factors can be predicted through lipid profile measuring. Thus, the aim of this study was to investigate the effects of 8 weeks aerobic training on lipid profile in patients with RA.Materials and Methods: In a quasi-experimental design, twenty three women (mean age 51.96±7.73 years, mean weight 72.37±10 kg and mean BMI 28.46±2.95kg/m2) with diagnosed RA for more than three years, who used the same medicine at the same dose, were purposefully selected as subjects and were randomly divided into experimental (n=11) and control groups (n=12). The experimental group participated in aerobic training at an intensity corresponding to 60-70% of their maximal heart rate reserve using a stationary bicycle (3 d/wk for 8 weeks). A fasting blood sample was collected prior to and after 8 weeks of aerobic training. Within group differences were analyzed by paired samples t-test and the between group differences by independent samples t-test.Results: TG, TC, LDL-C, TC / HDL-C, LDL-C/HDL-C levels and BMI levels decreased and the HDL-C increased significantly in the experimental group after 8 weeks of aerobic training (P<0.01). Within control group differences showed that TC, TG and LDL-C increased significantly (P<0.05); TC / HDL-C and LDL-C/HDL-C increased significantly (P<0.01); HDL-C decreased significantly (P<0.05) and BMI hadn't any significant changes (P<0.05).Conclusion: These results indicate that aerobic training may play an effective role in Lipid profile improving through the prevention and decrease of CVD in patients with RA.Performing aerobic training may neutralize the effects of physical inactivity and drug side effects on lipid profile. Furthermore, it was found that patients with RA as well as other people can improve their cardiovascular health through performing aerobic training.

Introduction: Evidence has shown that spread of cardio-vascular diseases has inflammatory background and systemic inflammation has the key role in the development of atherosclerosis and these factors may specially increase cardiovascular problems in overweight and obese people. This study examined the effects of resistance and aerobic trainings on soluble intracellular adhesive molecule (sICAM-1) and lipid profile in overweight women.Materials and methods: 38 healthy premenopausal women participated in the study and were randomly classified into two training groups including resistant group (n=14, mean age 34.14±5.82 yr., body mass index 30.48±4.29 kg/m2) and aerobic group (n=14, mean age 35.42±5.77 yr., body mass index 28.49±3.28 kg/m2), and a control group (n=10, mean age 35±5.94 yr., body mass index 26.98±2.17 kg/m2). Aerobic training was carried out for 8 weeks, 4 sessions per week at 65-80 percent of maximal reserve heart rate. The duration of each session was 16 minutes in the first week and it increased up to 30 minutes in the 8th week of exercise. Resistance training was also carried out for 8 weeks at 50-65 percent of 1RM. The training was carried out 4 session per week and each session lasted 50 minutes and included 9 stations. sICAM-1, lipid profiles including total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and body mass index of participants were assessed before and 48 hours after trainings. Data were analyzed by the use of ANOVA and LSD test and statistical significance was put at P<0.05.Results: Weight (P=0.001) and body mass index (P=0.001) decreased and maximal oxygen uptake (P=0.001) increased significantly in both aerobic and resistance groups after 8 weeks, while sICAM-1, triglyceride, total cholesterol, HDL-C and LDL-C had no significant changes (P>0.05) in training groups than control group.Conclusion: Although the 8 weeks training did not have significant effects on the lipid profile and sICAM-1 of overweight premenopausal women, body mass index decreased and maximal oxygen uptake improved significantly in the two groups.

Introduction: Acylated ghrelin and peptide YY are hormones that influence food intake.The aim of this study was to investigate the effect of single exhaustion exercise session on appetite, plasma acylated ghrelin and peptide YY.Materials and methods: Twenty three male (age 19.58±2.12 yr, BMI 21.63±2.7 kg/m2 and weight 64.86±6.46 kg) performed an exhaustion session running with 60-85% intensity of maximal heart rate. Blood samples were taken before and immediately after exhaustion exercise.Results: Exhaustion exercise causes significant decrease of plasma acylated ghrelin (P= 0.023), PYY (P=0.021) and also increase of appetite (P=0.001).Conclusion: Suppression of acylated ghrelin and increase of appetite after exercise shows significant negative relationship between the two shows. With the exception of possible physiological factors, other factors appear to be involved in regulating appetite.

Animal studies are a first step for clinical trials in many human research areas. Researchers who use animals in their studies must calculate, determine and justify the number of animals to be used. Animal ethical committees will review research proposals using animals in their studies in order to make sure that an appropriate number of animals are used. This brief article intends to discuss the methods of determination of the number of animals with regard to previous studies and the power of the sample size. It is noteworthy that even in complex experimental studies which need complicated statistical models, sample size determination can be calculated by simple formulas. Sample size determination and the relateds formula in various types of hypothesis are described in this study. The aim of the study is to offer appropriate statistical methods for determining the least number of animals which could be used in a study for effective tests of the research hypotheses. Finally, some effective simple formulas for the determination of accurate sample sizes are introduced.