فهرست مطالب

  • Volume:2 Issue:1, 2019
  • تاریخ انتشار: 1398/04/24
  • تعداد عناوین: 8
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  • Khaled Trabelsi, Hamdi Chtourou * Page 1
    Teenage students continue to participate in physical education lessons during the month of Ramadan. The combination of intermittent fasting and physical activity may result in impairment in both physical and cognitive performances. Additionally, dietary intake, sleep and hydration status may be negatively affected. To counteract the possible negative effects of intermittent fasting upon health and athletic performance of adolescent students, some practical recommendations should be outlined including (i) nutrition and sleep education of students, (ii) reducing the intensity and increasing the recovery periods during physical education lessons and (iii) practicing physical education in indoor. Additionally, teachers should be aware of clinical signs and symptoms of dehydration and hypoglycemia.
    Keywords: Ramadan Observance, Hydration, Metabolism, Performance, Recommendations, Physical Education
  • Majid Jahani, Maghsoud Nabilpour, Rodrigo Ramirez Campillo * Page 2
    Background
    L-arginine is a precursor to nitric oxide, which can affect some hemodynamic indices.
    Objectives
    The purpose of this study was to investigate the effect of one-month aerobic training with and without supplementation of L-arginine on hemodynamic indices in obese men.
    Methods
    A quasi-experimental double-blind, study was carried out. Subjects (age, 30 - 45 years; BMI, 38 - 40 kg.m-2) were randomly assigned to an exercise and L-arginine supplementation group (n = 10) and placebo group (n = 10). Before and after four weeks of aerobic exercise (three 90 - 120 min sessions per week at 65% - 85% of maximal heart rate), systolic and diastolic blood pressure, and rate pressure product (RPP) were measured at rest. The analysis of variance was used to determine the interaction between the two factors of exercise and supplementation of L-arginine on the dependent variables at P < 0.05.
    Results
    Four weeks of aerobic exercise reduced the RPP in both groups (P ≤ 0.05), while the L-arginine group significantly reduced systolic blood pressure (116.6 ± 3.40), diastolic blood pressure (76 ± 2.29) and RPP (8918.2 ± 722.86).
    Conclusions
    L-arginine supplementation along with four weeks of aerobic exercise can be effective in controlling hypertensive of obese men.
    Keywords: Aerobic Exercises, L-arginine, Blood Pressure
  • Mansour Sayyah *, Zarichehr Vakili, Hasan Ehtram, Fahimeh Sarbandi, Zahra Amooyi Page 3
    Objectives
    The aim of this research was to determine the effect of two months of intermittent aerobic exercise on cortisol and testosterone hormones.
    Methods
    Twenty healthy sedentary volunteer male subjects (age: 22.2 ± 3.2; height: 174.5 ± 4.6 cm) participated in this research. They were randomly assigned into two groups of experimental and control conditions. Fasting blood sample was drawn prior to the start of the exercise program from both groups. The experimental group participated in 8 consecutive weeks of intermittent aerobic exercise running 4 distances of 200 meter with rest interval between each run. The running distance increased 400 meter weekly. At the end of the program, fasting blood samples was obtained to measure the testosterone and cortisol hormone.
    Results
    The results of analysis indicated that no significant changes occurred in the mean value of serum testosterone of both groups in the experimental and control group (P > 0.05). However, the exercise condition caused a significant change in the mean value of serum cortisol in the exercising group (P = 0.0001).
    Conclusions
    The significant change in cortisol was associated with significant weight loss in the exercise group suggesting that this condition caused inflammation in addition to the fat catabolism in the exercised group.
    Keywords: Exercise, Cortisol, Testosterone
  • WITHDRAWN: Effect of Different Methods of Training in Body Composition and Lipid Profile in Occupational Men
    Marjiana Angela Zin, Gisele Maria Tonin da Costa, Andrigo Zaar * Page 4
  • Lovro Štefan, Mario Baić *, Damir Pekas Page 5
    Objectives
    The aim of this research was to estimate the validity of measured and self-reported height, weight and body-mass index (BMI) in Croatian adolescents.
    Methods
    In this cross-sectional study, participants were 286 urban secondary-school students (53% of girls) from the city of Zagreb, Croatia. To assess self-reported height, weight and sociodemographic characteristics of the participants, an in-person interview was carried out.
    Results
    Both boys and girls underestimated weight and height. Cohen’s D effect showed that these differences were trivial. Pearson’s coefficient of correlation between self-reported and measured values ranged from 0.95 to 0.97 in both boys and girls. The prevalence of underweight was overestimated, when using personal assessment of BMI, while overweight status was underestimated by both gender. Kappa statistics showed good (0.64 in girls) and excellent (0.89 in boys) agreement between the self-reported and measured BMI.
    Conclusions
    Our findings suggest, that there is the inaccuracy between measured and personal assessment of height and weight to determine the prevalence of overweight/obesity, especially in girls. However, self-reported height, weight and calculated BMI may be used as a valid assessment for large epidemiological studies, but not for intervention purposes.
    Keywords: Validity, Effect, Agreement, Secondary-School Students, Croatia, Differences
  • Surojit Sarkar, Swapan Kumar Dey * Page 6
    Background
    Scientific researches available on anthropometric and physiological characteristics of female rugby players in India are very scanty.
    Objectives
    The present study was aimed to evaluate and compared different anthropometric, body composition and physical fitness parameters and also to investigate whether any distinctive characteristics exist among above variables according to their specific playing position.
    Methods
    Twenty five Indian national women rugby players (forward, n = 12, mean age = 20.9 ± 3.30 and back, n = 13, mean age = 19.7 ± 2.48) of pre-competitive phase were chosen as subject from the national coaching camp. They were evaluated for various anthropometric, body composition parameters, hemoglobin, blood glucose level and physical fitness profile by following standard procedure.
    Results
    Forward players had significantly higher body weight, BMI, fat percentage, sum of skinfold, total body potassium, total body calcium and glycogen content as compared to the back. Whereas, players of back position had significantly higher relative muscle mass (MM/Wt.), relative body cell mass (BCM/Wt.), agility, standing broad jump, VO2max and relative peak anaerobic power than their forward counterparts. Linear regression model identified agility (β = 0.59) and sum of skinfold (β = -0.45) as significant predictor of peak anaerobic power (adjusted R2 = 0.61) of these players.
    Conclusions
    Present study indicated the players of back position were faster, more agile and aerobically fit with having lower body weight and fat percent as compared to their forward counterparts. Whereas, principal component analysis identified BMI, sum of skinfold and agility as the main confounding variables to categorize the present rugby players between forward and back positional groups.
    Keywords: Agility, Sum of Skinfold, Leg Explosive Power, Relative Peak Anaerobic Power, VO2max
  • Mohsen Jafari * Page 7
    Background
    White blood cells count (WBC), platelet count (Plt) and red blood cells distribution width (RDW) are some emerging atherosclerosis risk factors.
    Objectives
    The purpose of this research was to study the effects of three months running exercise on these variables in untrained overweight middle-aged men.
    Methods
    Subjects were divided in groups of control (n = 10) and exercise (n = 11). In experimental group, subjects performed twelve weeks (three times per week) running exercise (intensity was between 75% to 85% of maximum heart rate). Blood samples were collected 24 hours before and 48 hours after exercises. Paired t-test was used for analysis of data in SPSS V. 15.
    Results
    Statistical analysis showed significant reduction of RDW and BMI, also significant elevation of WBC, Plt and VO2max after three months exercise in the experimental group (P ≤ 0.05); no significant changes was observed in the control group (P > 0.05).
    Conclusions
    In general, three months running exercise may improve blood cells (leucocytes, erythrocytes and platelets) function that may lead to reduction of cardiovascular events risk in middle-aged men, but certainly more research is needed for precise conclusion.
    Keywords: Leukocyte, Platelet, Erythrocyte, Running, Untrained Men
  • Boukhemis Boukelia *, Abdelhakim Sabba, Mark Fogarty Page 8
    Objectives
    Fasting is usually associated with changes in the metabolic, psychological and physiological responses of athletes; advancing and/or delaying their biological clock and therefore, affecting their sport performance. The aim of this study was to assess the effect of Ramadan fasting on blood glucose level, mean arterial pressure (MAP), heart rate (HR) and skin temperature in 11 experienced endurance athletes.
    Methods
    The study was conducted during the third and fourth weeks of Ramadan (26 May - 24 June 2017). Eleven northwest African male endurance runners volunteered to participate in this study (mean ± SD: Age 32 ± 8 years, mass 64 ± 5 kg, and height 1.72 ± 0.05 cm). All participants regularly trained between 18:00 - 19:00; aiming to complete their training close to the time of breaking of fast to allow for rapid rehydration and avoiding any health complications. Blood finger-pricking, blood pressure (BP), HR and skin temperature samples were taken every 2 hours over a 24-hour period during the 3rd or 4th weeks of Ramadan. Data were analysed using a two-way repeated measures ANOVA with Bonferroni-adjusted post hoc tests.
    Results
    A clear within-day variation was revealed in blood glucose concentrations and HR (P < 0.05). Blood glucose concentration variation was directly associated with exercise and food intake but significant peaks were also observed prior to breaking fast. These peaks corresponded to the start of athlete’s usual daily routine and suggest the athletes were able to phase advance blood glucose circadian rhythms.
    Conclusions
    The data presented demonstrates the combination of exercise and fasting phase shifted and adjusted the blood glucose concentration to start rising prior to training session.
    Keywords: Blood Glucose, Fasting, Circadian Rhythm