Relationship between maximal oxygen uptake and oxygen uptake attained during treadmill middle-distance running

Traditionally, it has been assumed that during middle-distance running oxygen uptake (VO2) reaches its maximal value (VO2max) providing the event is of a sufficient duration; however, this assumption is largely based on observations in individuals with a relatively low VO2max. The aim of this study was to determine whether VO2max is related to the VO2 attained (i.e. VO2peak) during middle-distance running on a treadmill. Fifteen well-trained male runners (age 23.3 +/- 3.8 years, height 1.80 +/- 0.10 m, body mass 76.9 +/- 10.6 kg) volunteered to participate in the study. The participants undertook two 800-m trials to examine the reproducibility of the VO2 response. These two trials, together with a progressive test to determine VO2max, were completed in a randomized order. Oxygen uptake was determined throughout each test using 15-s Douglas bag collections. Following the application of a 30-s rolling average, the highest VO2 during the progressive test (i.e. VO2max) was compared with the highest VO2 during the 800-m trials (i.e. VO2peak) to examine the relationship between VO2max and the VO2 attained in the 800-m trials. For the 15 runners, VO2max was 58.9 +/- 7.1 ml x kg(-1) x min(-1). Two groups were formed using a median split based on VO2max. For the high and low VO2max groups, VO2max was 65.7 +/- 3.0 and 52.4 +/- 1.8 ml x kg(-1) x min(-1) respectively. The limits of agreement (95%) for test-retest reproducibility for the VO2 attained during the 800-m trials were +/- 3.5 ml x kg(-1) x min(-1) for a VO2peak of 50.6 ml x kg(-1) x min(-1) (the mean VO2peak for the low VO2max group) and +/- 2.3 ml x kg(-1) x min(-1) for a VO2peak of 59.0 ml x kg(-1) x min(-1) (the mean VO2peak for the high VO2max group), with a bias in VO2peak between the 800-m runs (i.e. the mean difference) of 1.2 ml x kg(-1) x min(-1). The VO2peak for the 800-m runs was 54.8 +/- 4.9 ml x kg(-1) x min(-1) for all 15 runners. For the high and low VO2max groups, VO2peak was 59.0 +/- 3.3 ml x kg(-1) x min(-1) (i.e. 90% VO2max) and 50.6 +/- 2.0 ml x kg(-1) x min(-1) (i.e. 97% VO2max) respectively. The negative relationship (-0.77) between VO2max and % VO2max attained for all 15 runners was significant (P = 0.001). These results demonstrate that (i) reproducibility is good and (ii) that VO2max is related to the %VO2max achieved, with participants with a higher VO2max achieving a lower %VO2max in an 800-m trial on a treadmill.     

An objective method for depicting team performance in elite professional rugby union

Using a two-study approach, we examined a methodology for objectively depicting team performance and form in a professional rugby union side. Study 1 developed standardized indicators to examine a team's performance in a single match relative to their previous matches over a domestic season via a performance report and form chart. This resulted in standardized performance indicators that provided instant and coherent feedback on the team's performance relative to previous standards. Study 2 then utilized this methodology to compare a match between two professional sides, played the following season, to assess the extent to which the performance by one team affected that of the other. Comparison of the two teams' performances, for the match they played against each other, identified a drop in relative performance (against previous standards) for both teams on the same performance indicators. This appeared to be due to the match being a close, hard-fought contest particularly in the tackle and around the gain-line. The findings of the two studies suggest an accurate and viable methodology for depicting team performance that is superior to the global measures previously adopted. Presenting teams' current standardized performances (i.e. form) on a single visual scale also has utility for coaches within an applied setting. Future research should further investigate the effect of one team's performance on another through both individual and team outcomes.     

牛津城

牛津是世界上最著名的英国城市之一，它有许多壮观无比的大学建筑，还有许多引人入胜的地方……     

Gender differences among sagittal plane knee kinematic and ground reaction force characteristics during a rapid sprint and cut maneuver

Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz). Differences (p < . 05) were observed between groups for knee flexion at contact and GRF at maximum knee flexion. Women averaged 5.8 degrees less flexion at contact and 1.0 N. (kg x m x s(-1))(-1) greater GRF at maximum flexion. Knee range of motion and peak GRF variables were not significantly different, but women had greater values. Women exhibited technique characteristics believed to increase ACL injury risk, but men exhibiting similar characteristics were also observed and could also be at risk.     

青少年运动缺乏症研究的10大问题

摘要：运动缺乏症（EDD）是一种儿科疾病,特点是中高强度体力活动（MVPA）下降,低于目前的推荐量,也与积极的健康结果（health outcomes）不一致。目前,大多数儿童和青少年符合EDD的诊断标准,因为他们没有达到日常MVPA的最低要求。本文的目的是强调10个与青少年EDD有关的重要研究问题。需要进行重要的研究来更好的定义EDD的临床表现,包括评估体力活动行以确定开始出现EDD的年龄或发育阶段;包括运动技巧和体能的运动起源（kinesiogenesis）的检测;以及对影响青少年MVPA的生活方式因素的评估。关于治疗EDD的干预措施和政策的研究问题,包括评估对卫生保健从业者进行运动医学重要性的教育和训练;确定在临床上识别和治疗EDD青少年的方法的有效性;开发敏感的、特效的、经济的方法以诊断青少年EDD;以及定制方法以促进本病诊疗的医疗保险赔付。如果未来研究不能优化EDD青少年的识别、治疗和管理方案,具有重大影响的生物医学、心理、经济和政治的新的卫生保健问题将会不断出现。     

无损检测市场的发展趋势

无损检测(NDT)对于飞机制造业和维修业来说是一个非常重要的行业,其年市值高达十几亿美元。而未来无损检测将如何适应越来越多的新材料、智能新技术的发展,值得关注。     

参考文献体例的两种组织形式

参考文献表的编排有多种体例形式，并且不同体例中参考文献各著录项的表达也不尽相同。由于期刊大都倾向于采用自己所特定的参考文献著录格式，因而目前已有的参考文献软件并不能给予作者很多帮助，即作者如果将其稿件由某期刊改投到另一种期刊，通常需要改动其中的参考文献表格式和正文中的相关部分。在众多的参考文献表格式中，有两种最为主要。其一是在人文科学中较为常用的哈佛体系(即著者一出版年体系)，该体系规定正文中给出引文的作者和出版年，文献书目中的引文按著者姓名的字母顺序和出版年的先后排列。另外一种主要的参考文献表是数字体系(顺序编码制)，即正文中给出引文的序号，参考文献表中的各篇文献按其在正文中出现的先后顺序排列。科技论文和医学论文多采用该种体例。本文列举了上述两种体例的格式，并对比了二者的优缺点，认为著者．出版年体系可以使学术论文的读者很方便地了解作者所引用的工作是由谁完成的，而数字体系(顺序编码制)因为简洁，从而可以使读者更为通畅地阅读论文。     

祖父遗信致五孙 生活经验飨吾人

正【阅读难度:】爱尔兰作家、诗人詹姆斯·K·弗拉纳根在即将走到生命尽头之时,为年幼的孙子与孙女留下了一封浓缩自己人生智慧的信。在这短短一封信中,我们读到了詹姆斯对人生的深切感悟,体会到了他对生命的热爱与留恋,最重要的,我们感受到了这位临终老人对后辈发自内心的无私关爱与期许。这朴实却不乏深刻的18条人生箴言,虽然是詹姆斯留给后代的     

全球十大精彩节日（上）

沙漠中的节日，马里（1月） 为期三天的“世界上最偏远的音乐节”每年在廷巴克图往北65公里处的撒哈拉沙漠的一块荒芜沙地上举行，称它为沙漠中的节日再合适不过了。从一个与世隔绝的偏僻小镇到音乐节举办地，乘吉普车需要半天的时间，如果你的屁股能够忍受得了，你也可以选择骑骆驼去，不过要花上三天的时间。     

自然与艺术

无论是色彩还是形状，大自然都像键盘包含所有音乐的音符一样，蕴涵有所有绘画的成分。艺术家的天职就是从这些成分中精心选择，然后将它们巧妙地结合起来，构成一幅美丽的图画。这就如同音乐家用音符从无序的声音中创作出动听而和谐的乐曲一般。如果说画家可以依照大自然本来的样子去创作，那么演奏家也就可以坐在钢琴上了……