The influence of a 6.5% carbohydrate-electrolyte solution on performance of prolonged intermittent high-intensity running at 30 degrees C     

Morris JG  Nevill ME  Thompson D  Collie J  Williams C 《Journal of sports sciences》2003,21(5):371-381

Nine male student games players consumed either flavoured water (0.1 g carbohydrate, Na+ 6 mmol x l(-1)), a solution containing 6.5% carbohydrate-electrolytes (6.5 g carbohydrate, Na+ 21 mmol x l(-1)) or a taste placebo (Na+ 2 mmol x l(-1)) during an intermittent shuttle test performed on three separate occasions at an ambient temperature of 30 degrees C (dry bulb). The test involved five 15-min sets of repeated cycles of walking and variable speed running, each separated by a 4-min rest (part A of the test), followed by 60 s run/60 s rest until exhaustion (part B of the test). The participants drank 6.5 ml x kg(-1) of fluid as a bolus just before exercise and thereafter 4.5 ml x kg(-1) during every exercise set and rest period (19 min). There was a trial order effect. The total distance completed by the participants was greater in trial 3 (8441 +/- 873 m) than in trial 1 (6839 +/- 512, P < 0.05). This represented a 19% improvement in exercise capacity. However, the trials were performed in a random counterbalanced order and the participants completed 8634 +/- 653 m, 7786 +/- 741 m and 7099 +/- 647 m in the flavoured water (FW), placebo (P) and carbohydrate-electrolyte (CE) trials, respectively (P = 0.08). Sprint performance was not different between the trials but was impaired over time (FW vs P vs CE: set 1, 2.41 +/- 0.02 vs 2.39 +/- 0.03 vs 2.39 +/- 0.03 s; end set, 2.46 +/- 0.03 vs 2.47 +/- 0.03 vs 2.47 +/- 0.02 s; main effect time, P < 0.01). The rate of rise in rectal temperature was greater in the carbohydrate-electrolyte trial (rise in rectal temperature/duration of trial, degrees C x h(-1); FW vs CE, P < 0.05; P vs CE, N.S.). Blood glucose concentrations were higher in the carbohydrate-electrolyte than in the other two trials (FW vs P vs CE:rest, 4.4 +/- 0.1 vs 4.3 +/- 0.1 vs 4.2 +/- 0.1 mmol x l(-1); end of exercise, 5.4 +/- 0.3 vs 6.4 +/- 0.6 vs 7.2 +/- 0.5 mmol x l(-1); main effect trial, P < 0.05; main effect time, P < 0.01). Plasma free fatty acid concentrations at the end of exercise were lower in the carbohydrate-electrolyte trial than in the other two trials (FW vs P vs CE: 0.57 +/- 0.08 vs 0.53 +/- 0.11 vs 0.29 +/- 0.04 mmol x l(-1); interaction, P < 0.01). The correlation between the rate of rise in rectal temperature (degrees C x h(-1)) and the distance completed was -0.91, -0.92 and -0.96 in the flavoured water, placebo and carbohydrate-electrolyte conditions, respectively (P < 0.01). Heart rate, blood pressure, plasma ammonia, blood lactate, plasma volume and rate of perceived exertion were not different between the three fluid trials. Although drinking the carbohydrate-electrolyte solution induced greater metabolic changes than the flavoured water and placebo solutions, it is unlikely that in these unacclimated males carbohydrate availability was a limiting factor in the performance of intermittent running in hot environmental conditions.  相似文献   

Self-defense and martial arts evaluation for college women: preliminary validation of perceptions of dangerous situations scale     

Hughes PP  Sherrill C  Myers B  Rowe N  Marshall D 《Research quarterly for exercise and sport》2003,74(2):153-164

Martial arts and self-defense programs train fearful people, especially women, to be more competent and confident to defend themselves in dangerous situations. However, there are no validated instruments to evaluate the effectiveness of programs purporting to teach self-protection. The Perceptions of Dangerous Situations Scale (PDSS), composed of fear, likelihood and confidence subscales, was developed and validated for university women. Participants were 368 university women, ages 17 to 45 years (M age = 20.7 years). Content validity of the PDSS was established through an expert panel, and construct validity was established through principal components analysis and determination of instructional sensitivity. Reliability was established through alpha coefficients. The PDSS, when used with university women, offers promising measurement opportunities in self-defense and martial arts settings.  相似文献   

Warm-up with baseball bats of varying moments of inertia: effect on bat velocity and swing pattern     

Southard D  Groomer L 《Research quarterly for exercise and sport》2003,74(3):270-276

The purpose of this study was to determine if warm-up with baseball bats of different moments of inertia has an effect on swing pattern and bat velocity. Ten experienced baseball players (ages 20-25 years) voluntarily participated in this study. Each participant was required to complete 10 dry swings (5 warm-up and 5 postwarm-up) at maximum effort within 3 different conditions. Post warm-up was always with a standard bat (I = .27 kgm2; 83.8 cm, 9.1 N). Warm-up for Condition 1 was with the standard bat. Condition 2 required participants to warm up with a standard bat plus a 6.1 N lead donut (I = .49 kgm2, 83.8 cm, 15.6 N). Condition 3 required participants to warm up with a hollow plastic bat (I = .08 kgm2; 83.8 cm, 3.34 N). Quantitative and qualitative analyses indicated that following warm-up with the weighted bat (largest moment of inertia), swing pattern was significantly altered, and post warm-up velocity was the lowest of the three conditions.  相似文献   

Non use of health information kiosks examined in an information needs context     

Williams P  Nicholas D  Huntington P 《Health information and libraries journal》2003,20(2):95-103

Whilst great emphasis has rightly been placed on the increased availability and use of health information, little research has been undertaken into the non use of such material, particularly with regard to electronic sources. Computer transactional log data from health information touch screen kiosks, collected as part of an ongoing Department of Health-funded study being carried out by City University, showed that females in the 55-74 age group were particularly under-represented as users. To explore reasons for this, in-depth interviews were carried out with 13 non-kiosk-using, primary-care out-patients fitting this profile, at a surgery which had a kiosk that was being monitored. Subjects were interviewed at length about their information needs and information-seeking behaviour, to determine reasons (if any) they might have had for non-kiosk use. The study utilized an interview schedule and technique loosely based on the 'Sense-Making' methodology of Brenda Dervin (Talk Presented at the International Communication Association Annual Meeting, May 1983, Dallas, Texas, USA. Available from: http://communicationsbsohio-stateedu/sense-making/art/artdervin83html.). Findings elicited many factors accounting for non use of the system. The first and major source of information remained the doctor, with written or other sources only being consulted where recommended or provided. There was evidence that patients wanted little more than the minimum information or instructions required to deal with their condition. Many appeared unaware of the presence of the kiosk and others assumed either that it was not for patient use or that it would not serve their needs. The methodology proved itself, with certain caveats, to be an appropriate vehicle for this kind of exploratory work.  相似文献   

The Maine electronic document delivery project: a cooperative project of Maine hospital libraries and the NN/LM New England Region     

Goldstein M  Sibley D 《Medical reference services quarterly》2003,22(3):53-62

The article discusses an Ariel document delivery project with seven Maine hospital libraries, the University of Massachusetts Medical School Library (UMass), and the New England Regional office of the National Network of Libraries of Medicine. Funding was awarded to six network members to purchase equipment or Ariel software. UMass served as a document provider. During the test, libraries received documents from UMass via Ariel or via the Web as a PDF document. This form of document delivery was faster than standard service with better quality of delivered articles. The column describes the project and outlines possible future steps.  相似文献   

治治高校的“官场病”   总被引：2，自引：0，他引：2  

刘文瑞  胡为 《出版参考》2005,(10):18-19

“官场病”导致学术精神的沦丧。作为学者必备的基本素养，被官场规则消磨得所剩无几；至于学者的道德良知、社会责任，更是被官场染缸改变了颜色。  相似文献   

万情涌流 一刊所系——《柳叶刀中文版》创刊记     

马可为 《出版广角》2004,(8)

要将这样一本权威、优秀的王牌期刊办成中国读者接受并喜爱的杂志,做到“承载学术,传播新知,福祉国人”,光靠拥有“敢为天下先”的勇气是远远不够的,必须要有更多力量的注入、更多才智的加盟,以及更加高屋建瓴的指导、更加严格细致的指正。  相似文献   

"分裂性创新"启示     

杨晓白  斯科特·D·安东尼  克拉克·G·吉尔伯特 《青年记者》2006,(3):67-68

报业在历史上曾经几次被预言将要灭亡。75年前,广播的出现是对报纸的威胁;50年前,电视成为报纸的威胁;10年前,因特网又出现了。然而整个过程中,报业不光生存下来了,而且今天仍然以令很多产业艳羡的利润率生存发展着。然而,如今人们普遍认同的一点是:报纸的主营业务的盈利能力将  相似文献   

为下一个视频体验时代做准备(节选)     

伍侃为 《视听界》2006,(6)

Agenda(报告议程)Connected Home Solutions Business/宽带联网事业部的业务Market Overview/市场概述New Requirements:Opportunity and Challenges/新的市场需求:机遇和挑战The Motorola VOD/TOD Solution摩托罗拉视频点播/电视点播方案Our VisionBe the global leader in broadbandConnected Home solutions and services,Product Portfolio for End to End Architecture enabling network convergence and seamless mobilitymarket leadership in key convergence categories#1digital set-tops50M+shipped#1digital video…  相似文献   

Kinematic analysis of butterfly turns of international and national swimmers     

Tourny-Chollet C  Chollet D  Hogie S  Papparodopoulos C 《Journal of sports sciences》2002,20(5):383-390

The aims of this study were (1) to evaluate the different turn phases of 200 m butterfly during competition in a 50 m pool, (2) to determine if wall contact times are related to swim speed and (3) to compare the turn variables of a European Champion with other swimmers. In the first part of the study, we assessed the turns of 22 swimmers ranked in three groups according to 200 m butterfly swim performance (fast group = 121.73+/-3.03 s, intermediate group = 126.25+/-0.55 s, slow group = 129.24+/-2.30 s). Two turn times were recorded: the first before the turn (i.e. the time it takes the swimmer's head to reach the wall from 7.5 m away) and the second after the turn (i.e. the time from the wall to the point at which the swimmer's head passes 7.5 m away). The third turn was performed significantly faster by the fast group than by the slow group, both before (P< 0.01) and after (P< 0.02) the turn. In the second part of the study, objectives (2) and (3) were evaluated among 15 swimmers based on a specific protocol. Three cameras (50 Hz) simultaneously recorded the turn; these were placed above the water 10 m before the wall, 5 m before and just above the wall. Longer contact times of the feet on the wall were associated with a faster push-off speed (P < 0. 02). The European Champion achieved an improved contact time while performing a rapid pull-out speed.  相似文献