درخت حوزه‌های تخصصی

Purpose: Sleep and exercise influence each other through complex interactions. Sleep disorders incidence in athletes are high among several sports. Method: 24 CrossFit practitioners, of both genders, between the ages of 25 and 35, presenting difficulty in initiating sleep, with a total sleep time of less than 6 hours per night, were recruited into a double-blind, randomized, placebo-controlled trial that lasted 8 weeks. Participants received capsules containing 3 mg of melatonin + 1200 mg of GABA (gamma-Aminobutyric acid) or placebo at 10:00 pm daily. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), cortisol and testosterone levels were measured and total-body skeletal muscle mass (TBSMM) by Lee’s equation performed by two different examiners. Results: Group melatonin + GABA gained an average of 600g of TBSMM while the control group lost 200g (p = 0.295). Both groups improve PSQI score (p = 0.007). No difference was found in cortisol and testosterone level. Conclusions: Although there was a difference between groups about TBSMM, it wasn’t statistically significant. Further studies will be necessary to demonstrate evidence of increased TBSMM from better sleep quality, with a larger number of participants and a longer trial.

Background : High altitude environments can cause a range of physiological changes in the body, and adolescents may be particularly vulnerable to the effects of altitude sickness. Acetazolamide has been shown to be an effective treatment for altitude sickness, but further research is needed to determine its impact on physiological variables among adolescents at high altitude. Aim: The aim of this study was to investigate the effects of acetazolamide in adolescents over 17 days at high altitude. Materials and Methods: Twenty-five healthy adolescents volunteered for this study and were randomly separated into control group (CG, n=12) and acetazolamide group (AG, n=13). AG took 250mg of acetazolamide. Resting Heart Rate (RHR) and Acute Mountain Sickness (AMS) using the Lake Louise questionnaire were measured each morning and afternoon during field testing; Resting Blood Pressure (RBP) was measured each afternoon. Pre- and post-blood samples (haemoglobin (Hb) and haematocrit (Hct)) were taken at sea level (SL) one week before departure and within 40 hours on return to SL. Results : Significant differences between groups for RHR on days 2, 3 and 5; systolic blood pressures for day 4 and 13 ( P <0.05). No significant difference between groups for diastolic blood pressure, pre- and post-altitude for Hb, Hct and PV. AMS scores did not differ from the two groups except on morning of day 12 ( P <0.05). Discussion and Conclusion : Results revealed that acetazolamide did not significantly induce changes to adolescents’ AMS scores and physiological changes. However, adolescents may consume acetazolamide to achieve lower RHR that may enable them to accommodate to HA, prolonging exercise in similar environments.

Purpose: The adequate use of sport-related modern knowledge such as new findings regarding nutritional and dietary supplements is an essential prerequisite of success in modern professional sport. Methods: In this semi-experimental study, 11 nationally prominent Taekwondoin with 8 to 12 years of experience and profile of (Age: 20±6 years, height: 178±12 cm, weight: 67±11kg, wrist circumference: 17±1 cm) were selected as subjects. The level of blood lactate, the time and speed of execution of Poomsae forms, and the number of Momdollyos successfully performed in 20 seconds were measured separately in a pre-test phase, after the intake of a placebo, and after the consumption of supplement drink. Results: Statistical results showed that lactate levels significantly increased compare to pre-tests in both groups. Although this increasing was not significant between groups in Momdollyo (p=0.599) and Poomsae (p=0.303). Indeed, number of successfully executed and also time of performance were significantly different in both Momdollyo (P=0.000) and    Poomsae (P=0.033). Conclusion: Intake of discussed customized decaffeinated supplement drink increased speed and number of execution of Poomsae forms and Momdollyo techniques but it seems that lactate levels depends on other factors in taekwondoin.

The first report showing that long-term endurance exercise increases oxidative stress in humans was published more than 4 decades ago. Since this discovery, many subsequent studies have confirmed the fact that muscle activity increases the production of reactive oxygen species (ROS) and leads to oxidative stress in multiple tissues, including blood and skeletal muscle. Although several tissues may contribute to exercise-induced ROS production, muscle contractions are predicted to stimulate ROS production in active muscle fibers, and skeletal muscle is the major source of ROS production during exercise. This contraction-induced ROS production is associated with 1. oxidant damage in several tissues (eg, increased protein oxidation and lipid peroxidation), 2. accelerated muscle fatigue, and 3. activation of biochemical signaling pathways leading to adaptation. Exercise helps in tight muscle fibers, it is related. While our understanding of exercise and oxidative stress has advanced rapidly over the past decades, questions remain as to whether exercise-induced increased ROS production is beneficial or detrimental to health. This review addresses this issue by discussing the site(s) of oxidant production during exercise and detailing the health consequences of exercise-induced ROS production.

The goal of this study was to compare the use of sports facilities of selected universities in Iran with some Canadian universities. This study was comparative and data collection was done through interviews with directors of physical education departments of the selected universities. All the universities studied in this paper are faced with a crisis of financial resources and revenue generation; however, a common weak point of Iranian universities is that they lack initial plan for efficient design as well as expert designers in construction of university spaces. Based on the findings, in the Canadian universities the facilities have the highest multi-purpose applications. Accordingly, practical and applicable recommendations have been suggested to office of development plans of Iran’s ministry of science, research and technology to improve the operation of sports facilities in Iranian universities.

The purpose of this study was to investigate the factors affecting the sudden buying of sportswear in sports stores in Mazandaran, Iran. This applied research has been done by descriptive-survey method. The statistical population of the study was the customers of a reputable sports store in Mazandaran province. 385 customers were selected through  available sampling method. A valid and reliable researcher-developed questionnaire was used for data collection, and structural equation modeling (SEM) was conducted for data analysis and hypotheses test. The results showed that the store environment (light, color, music, fragrance) has a positive effect on the sudden buying behavior of store customers. Moreover, the findings demonstrated that layout and physical appearance (Product availability, booth guide, product layout, building appearance, and staff coverage), as well as facilities available in the store and ancillary services (cafes and restaurants, amusement parks, child care centers), affect the psychological characteristics of customers' sudden buying behavior. By focusing on the research findings, the managers of sports stores can have a positive impact on customers’ sudden buying and improving the selling approaches.

The purpose of this study was to clarify and analyze the factors affecting the access of Zanjan province football teams to higher levels of national leagues in Iran. The method of this study was mixed. The research population consisted of 193 coaches and 18 members selected from chairpersons and secretaries of Zanjan province football associations. The sampling was purposive at the interview stage, but at the stage of distributing the questionnaire, given the limited number of first, second, and third-class coaches and also the limited number of chairpersons and secretaries of football associations, the samples were selected through total sampling approach and in the case of class 4 coaches, 108 subjects were chosen according to Morgan table. The research tool was only a questionnaire. The validity of the questionnaire was approved by 12 experts and its reliability was found to be 0.94 according to Cronbach's alpha. For data analysis, Kolmogorov-Smirnov, Binomial, and Friedman tests were used. The results of the research showed that among the general factors except for the research and education, the effect of other factors including economic, technical, facilities and equipment, managerial, psychological, social, and cultural, and among the minor factors, 22 out of 29 factors are significantly higher than the average. Considering the explained factors and investment in these factors can help the football teams in Zanjan province to promote to the higher Levels of national leagues in Iran.