不同方式运动与脑源性神经营养因子

脑源性神经营养因子是神经营养素家族中重要的神经生长因子,在神经可塑性方面有着重要作用。随着其生物学功能认识的不断深入,人们逐渐认识到运动刺激对脑源性神经营养因子在神经元中表达有影响。本文就近年来国内外有关不同方式运动与脑源性神经营养因子的相关研究现状作一综述。     

一氧化氮与运动疲劳关系的研究进展

一氧化氮(NO)是一种自由基,也是一种重要的细胞内信使分子,其参与许多生理过程,具有广泛的生物学效应。本文主要从NO对肌肉的外周机制和大脑的中枢机制两方面对运动性疲劳进行阐述,探讨了NO与运动性中枢疲劳的关系,并展望了其在消除运动性疲劳的意义。     

运动与血睾酮

血睾酮作为雄性激素的代表，与机体的运动能力有密切的关系。本文综述了血睾酮的生理特点、作用、以及运动对血睾酮影响的研究进展，旨在促进国内体育科学工作者对血睾酮有更深的理解、研究和应用     

Urea production during prolonged swimming

Male interscholastic swimmers (n = 8) completed a 4572 m training swim in 62 ±1.1 min (x ± s.e.) with terminal heart rate and blood lactate of 152 ± 6 beats min^‐1 and 6.9±0.89 mM, respectively. Sweat rate (0.48±0.0951. h^‐1) was lower than similar intensity cycling (1.5±0.13 1. h^‐1) or running (1.1 ± 0.14 l.h^‐1). Post‐swim serum urea N (11.6±0.71 mM) was elevated (P<0.05) vs pre‐swim (4.6±0.39 mM). Post‐swim urine volume (860±75 ml 24 h^‐1) was reduced (P<0.07) and resulted in an elevated (P<0.05), but delayed (24–84 h), post‐exercise urea N excretion. Although the reduced urine and sweat production during the swim undoubtedly contributed to the elevated serum urea, there must be another explanation because together they could only account for 38% of the observed increase. On the basis of the magnitude of serum urea increase, it appears that the swim caused an increase in urea production (amino acid oxidation). The failure to observe larger increases in urinary urea during recovery indicates that either urea excretion following exercise continues for prolonged periods of time (>48 h) or another significant mode of nitrogen excretion exists.     

Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right?), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.     

Nutritional strategies for promoting fat utilization and delaying the onset of fatigue during prolonged exercise

Carbohydrate ingestion before and during endurance exercise delays the onset of fatigue (reduced power output). Therefore, endurance athletes are recommended to ingest diets high in carbohydrate (70% of total energy) during competition and training. However, increasing the availability of plasma free fatty acids has been shown to slow the rate of muscle and liver glycogen depletion by promoting the utilization of fat. Ingested fat, in the form of long-chain (C 16-22 ) triacylglycerols, is largely unavailable during acute exercise, but medium-chain (C 8-10 ) triacylglycerols are rapidly absorbed and oxidized. We have shown that the ingestion of medium-chain triacylglycerols in combination with carbohydrate spares muscle carbohydrate stores during 2 h of submaximal (< 70% VO 2 peak) cycling exercise, and improves 40 km time-trial performance. These data suggest that by combining carbohydrate and medium-chain triacylglycerols as a pre-exercise supplement and as a nutritional supplement during exercise, fat oxidation will be enhanced, and endogenous carbohydrate will be spared. We have also examined the chronic metabolic adaptations and effects on substrate utilization and endurance performance when athletes ingest a diet that is high in fat (> 70% by energy). Dietary fat adaptation for a period of at least 2-4 weeks has resulted in a nearly two-fold increase in resistance to fatigue during prolonged, low- to moderate-intensity cycling (< 70% VO 2 peak). Moreover, preliminary studies suggest that mean cycling 20 km time-trial performance following prolonged submaximal exercise is enhanced by 80 s after dietary fat adaptation and 3 days of carbohydrate loading. Thus the relative contribution of fuel substrate to prolonged endurance activity may be modified by training, pre-exercise feeding, habitual diet, or by artificially altering the hormonal milieu or the availability of circulating fuels. The time course and dose-response of these effects on maximizing the oxidative contribution of fat for exercise metabolism and in exercise performance have not been systematically studied during moderate- to high-intensity exercise in humans.     

The influence of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill

The aim of this study was to examine the effect of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill. Nine semi-professional soccer players volunteered to participate in the study. Their mean (± _sx ) age, body mass and maximal oxygen uptake were 20.2 ± 0.4 years, 73.2 ± 1.8 kg and 59.1 ± 1.3 ml·kg^-1 ·min^-1 respectively. The players were allocated to two randomly assigned trials: ingesting or abstaining from fluid intake during a 90 min intermittent exercise protocol (Loughborough Intermittent Shuttle Test:LIST).This test was designed to simulate the minimum physical demands faced by soccer players during a game. Before and immediately after performance of the test,the players completed a soccer skill test and a mental concentration test. Performance of the soccer skill test after the 'no-fluid' trial deteriorated by 5% (P ? 0.05),but was maintained during the fluid trial. Mean heart rate, perceived exertion, serum aldosterone, osmolality, sodium and cortisol responses during the test were higher (P ? 0.05) in the 'no-fluid' trial than in the fluid trial. The results of this study suggest that soccer players should consume fluid throughout a game to help prevent a deterioration in skill performance.     

有氧健身操对中年女性身体成分和心肺功能的影响

通过对58名中年女性实施6个月的有氧健身操锻炼,探讨有氧健身操对中年女性身体成分和心肺功能的影响。结果显示,长期参加有氧健身操锻炼,可以降低体脂、静态心率及血压,提高台阶指数和肺容量,对预防中年女性心血管疾病具有重要作用。     

中英义务教育理科课程学生学习评价的比较研究

本文分析了英国义务教育理科课程评价体系的发展，在此基础上，从评价体系的整体结构、内容设计和内容构成三个方面与我国义务教育理科课程评价体系进行了比较。结果发现我国的评价体系在内容构成上有较大优势，而英国评价体系的整体结构很值得借鉴。     

Research and teaching cultures in two contrasting UK policy contexts: Academic life in Education Departments in five English and Scottish universities

The paper explores academic staff and departmental research and teaching cultures in the Education Departments of five universities in Scotland and England, countries with increasingly diverging public policies in respect of education. The relationship between research and teaching, how the purposes of universities are defined and the status of research in Education are current UK higher education policy preoccupations. Data is drawn from interviews with 40 academics, observation of department settings, documentation and websites. The analysis draws on the work of Bourdieu, considering the changing habitus of individual academics, their departmental and academic subject context and the forms of symbolic capital now required in Scottish and English Education departments in response to new policies affecting their academic field. The paper also utilises recent literature on the research–teaching relationship. The career trajectories of respondents, their habitus and the forms of symbolic capital that they bring to academic life are examined, as are the extent to which the teaching and research cultures in each of the five departments studied mirror each other and whether these also reflect the two different policy contexts. The themes how academic cultures are shaped and research/teaching connections viewed have international as UK relevance.