Power laws and athletic performance.

In a previous study, we showed that the 1992 men's world record running times in the 100 m to 200 km could be represented accurately by the equation T = cDn, where T is the calculated record time for distance D, and c and n are positive constants. Here, we extend that to cover the years 1925-65 at 10-year intervals and 1970-95 in 5-year intervals for distances of 100 m to 10 km. Values of n for all years lie along a straight line with a small negative slope. A regression analysis yields an equation for values of n covering the period 1925-95. Values of c from 1925 to 1995 were fitted by a quadratic equation. These two equations define a surface in three-dimensional space (log(T), log(D), data) for all men's world record runs over the 70-year period for distances of 100 m to 10 km. We also demonstrated previously that event times, t, do not scatter randomly with respect to the values of T but form a consistent pattern about the straight lines in log(T) versus log(D) plots. In this study, we show that the pattern of (t-T)/t as a function of date has remained constant for the past 70 years.     

Scaling laws and forecasting in athletic world records

In this study, we analysed running world records and found that the mean speed of the race, μ, as a function of the record time, τ, can be described asymptotically by two well-defined scaling laws of the form u ?s τ - β. There is a break in the scaling laws (?1000m) between the shorter and the longer races at a characteristic time of around 150-170 s, after which a new scaling regime emerges. This is the first occasion that this characteristic time has been clearly found in physical terms; we interpreted it as the transition time between the anaerobic and the aerobic energy expenditure of athletes. This phenomenon is independent of the athletes' sex and is also found in swimming races with similar values of the characteristic time. We also investigated the forecasting of world records using historical data. Using an approach based on the identification of non-Poissonian events for a sequence of temporal point processes, we found that the sequence of improvements in all athletic records from 1900 to the present day cannot be considered as a sequence of completely random events.     

山东省体育俱乐部的发展及面临的主要问题

介绍了山东省体育俱乐部的现状、发展进程、类型、作用与地位。山东省体育俱乐部面临的主要问题是：１）权属关系混乱,审批程序不清,不利于其长远发展;２）管理体制不顺,缺乏制度化、规范化和法规化,将影响其健康成长;３）自我发展、自我完善的意识不强,自身造血功能不足,致使部分俱乐部举步维艰。最后提出了推动山东体育俱乐部进一步发展的建议。     

Emotional intelligence,servant leadership,and development goal orientation in athletic directors

Scholars and policy makers have long considered sport as a vehicle for promoting young athletes’ well-being, educational experience, and citizenship skills. Athletic directors can play a significant role in this process by establishing organizational goals that can foster the development of young athletes and also by ensuring that other personnel abide by these goals. However, little is known about methods athletic directors can use to focus on such development goals in the midst of the current winning-at-all-costs culture surrounding sports. Thus, the purpose of this study is to examine the relationships between emotional intelligence, servant leadership, and development goal orientation among high school athletic directors. A total of 445 athletic directors located in 48 states in the United States completed an online survey. The results indicated that emotional intelligence is positively associated with servant leadership, which in turn is positively associated with development goal orientation. The mediation analysis also revealed that servant leadership fully mediates the relationship between emotional intelligence and development goal orientation among athletic directors. The findings of this research assist in understanding how sports governing bodies can educate athletic directors to initiate development-oriented reform of the winning-at-all-costs culture in sports.     

Peak athletic performance and ageing: Evidence from baseball

Abstract

Baseball players exhibit a pattern of improvement and decline in performance; however, differing lengths of careers and changes in rules and characteristics of the game complicate assessments of age-related effects on performance. This study attempts to isolate the impact of age on several player skills while controlling for relevant outside factors using longitudinal data from 86 seasons of Major League Baseball. The results indicate that players age in different skills in accord with studies of ageing in other athletic contests. For overall performance, multiple-regression estimates indicate that hitters and pitchers peak around the age of 29 – later than previous estimates. Athletic skills such as hitting and running peak earlier than skills that rely heavily on experience and knowledge, such as issuing and drawing walks.     

浅论格斗项目供能特点与竞技能力的关系

对格斗项目竞技能力的特征、供能特点以及格斗项目有氧、无氧能力与竞技能力的关系进行了探讨,认为格斗竞技能力是由七个主要因素综合作用的结果;有氧、无氧能力（结合专项特点和专项需要）水平的提高有利于创造优异成绩;良好的有氧能力,有利于提高运动员承担大负荷训练的水平和体能的恢复;无氧能力水平对格斗项目运动员水平的提高也有积极的重要意义。     

Athens 2004: the pollution climate and athletic performance

Athens sits in a basin approximately 450 km² in area, surrounded by mountains and open sea. Anthropogenic emissions in conjunction with the topographical and meteorological conditions can result in high air pollution within the city. The pollutants of concern for athletes competing in Athens 2004 appear to be nitrogen dioxide (NO₂), ozone and particulate (PM₁₀) pollution. Exposure to elevated ozone concentrations has been reported to give rise to symptoms that include cough, chest pain, difficulty in breathing, headache, eye irritation and a decrease in forced expiratory volume in one second. All of these effects are likely to impact upon performance, and several studies of cyclists suggest this to be the case. In contrast, the impact of ambient concentrations of NO₂ appears to be negligible on normal activities, but at high exercise intensities the impact remains unclear. The use of currently available information and models to predict the effect of ozone and other pollutants on elite athletes is problematical, since such models are based upon significantly lower ventilation rates than those achieved by some elite athletes. In addition, it is already known that the response to ozone can vary somewhat between individuals. Since the individuals who will be competing in Athens are physiologically very different to the participants in most published studies, it is difficult to predict individual responses. There is some evidence to indicate that adaptation to the adverse health and performance effects of ozone can occur, so that performance is partially recovered on re-exposure. The adaptation is not seen in all studies and appears to be dependent on several factors, including the initial sensitivity of the individual to ozone. Antioxidant supplementation has also been shown in some studies to partially ameliorate the adverse effects of ozone by counteracting the oxidative stress mechanism associated with this pollutant. Whether this transfers to performance enhancement per se remains unclear at present. Additional research is required to gain a sound understanding of the effects of a complex mixed air pollution exposure on the pulmonary function and performance of athletes exercising at high work intensities.     

The analysis of athletic performance: some practical and philosophical considerations

This article presents a hypothetical dialogue between a notational analyst (NA) recently schooled in the positivistic assessment of athletic performance, an ‘old-school’ traditional coach (TC) who favours subjective analysis, and a pragmatic educator (PE). The conversation opens with NA and TC debating the respective value of quantitative and qualitative methods of performance analysis. Having considered their arguments from a-distance, PE offers a philosophically underpinned point of view that helps to practically reconcile NA's and TC's opposing positions. While primarily focusing on practical issues relating to the analysis of athletic performance, PE contends that ‘quantitative’ and ‘qualitative’ approaches can be legitimately used in combination. Such a stance would appear in-line with a pragmatic philosophical perspective, which by focusing on practical issues embraces pluralistic methods. It is hoped that this dialogue will facilitate further philosophical and practical debate to generate knowledge that could enrich coaches' understanding by presenting an approach to performance analysis that is more realistic for practitioners.     

Defining advantage and athletic performance: The case of Oscar Pistorius

Abstract

Olympic style games were first held for athletes with disabilities in Rome in 1960. Today the Paralympic Games (parallel Olympics) feature competition for athletes from six disability groups, including amputee, visually impaired, and spinal cord injury. Olympic hosts, both summer and winter, are now contractually obliged to organize the Paralympics in the same venue. The size and popularity of the games have grown exponentially since their inception, but they remain largely separate from the Olympics themselves. Recently, a very successful Paralympic athlete from South Africa, Oscar Pistorius, made it clear that despite his double below-the-knee amputation he wanted to compete in his event (400 m) at the Olympics. Initially, however, Oscar Pistorius was prohibited from competing at any International Amateur Athletics Federation (IAAF) competition on grounds of fairness. On the basis of biomechanical and physiological evidence, the IAAF argued that his highly specialized prosthetic limbs gave him an advantage and were therefore in contravention of Rule 144.2. This rule forbids the use of any technical device (such as prosthetic limbs) that provides the user with an advantage over another athlete not using such a device. This decision was subsequently overturned by the Court of Arbitration for Sport following an appeal by Pistorius. Using this case as an example, the aim of this paper is to highlight the empirical and ethical difficulties associated with the application of the principle of fairness in sport. In particular, we discuss both the complexity of identifying the nature and size of athletic advantage and the basis for determining its validity. Moreover, we explore how similar difficulties arise when attempting to establish criteria for “relevant athletic performance”. We argue that reasonable rules and norms for competition are not simply inferred from the principle of fairness. Such rules and norms should result from careful judgements informed by scientific, conceptual, and ethical evidence, and be guided by the standards of excellence that best characterize the sport in question.     

我国职业篮球运动员转会制度及相关法律问题

将我国职业篮球联赛与国际上先进的联赛制度进行对比。分析我国当前职业篮球转会制度的优、缺点，对我国职业联赛转会过程中出现的纠纷从法律角度方面进行分析，提出我国的转会制度应加强立法工作。使转会制度趋于职业化、合理化、法制化。     

大用户直购电对清洁发电和用电节能的影响探讨

目前,随着我国电力市场改革的逐步深入,大用户直购电模式正在试点展开,但该模式尚存在管理办法不完善等问题,实施后可能对发电企业清洁发电及电力大用户电力节能产生一定的影响。本文分析了大用户直供电模式对发电侧、电网侧和用户侧产生的影响,尤其是大用户直购电模式将会对发电企业的清洁化改造和用能企业的节能化管理造成的影响。结果表明院大用户直供电模式可以有效降低电力用户用电成本,提高发电企业盈利能力,但尚需完成相关政策法规等保证大用户直供电模式实施后的节能减排工作。     

Evolution and revolution: Gauging the impact of technological and technical innovation on Olympic performance

Abstract

A number of studies have pointed to a plateauing of athletic performance, with the suggestion that further improvements will need to be driven by revolutions in technology or technique. In the present study, we examine post-war men's Olympic performance in jumping events (pole vault, long jump, high jump, triple jump) to determine whether performance has indeed plateaued and to present techniques, derived from models of human growth, for assessing the impact of technological and technical innovation over time (logistic and double logistic models of growth). Significantly, two of the events involve well-documented changes in technology (pole material in pole vault) or technique (the Fosbury Flop in high jump), while the other two do not. We find that in all four cases, performance appears to have plateaued and that no further “general” improvement should be expected. In the case of high jump, the double logistic model provides a convenient method for modelling and quantifying a performance intervention (in this case the Fosbury Flop). However, some shortcomings are revealed for pole vault, where evolutionary post-war improvements and innovation (fibre glass poles) were concurrent, preventing their separate identification in the model. In all four events, it is argued that further general growth in performance will indeed need to rely predominantly on technological or technical innovation.     

现行《体育法》与国民政府体育法规的比较及思考

研究以往体育法规,取其精华,去其糟粕,以完善我国体育法规建设,是我国体育法制工作的重要任务之一。通过对现行《体育法》与国民政府体育法规在总则、大众体育、学校体育、竞技体育、体育社会团体、保障条件和法律责任等7个方面的比较,分析了国民体育法规值得借鉴的地方,指出了现行体育法的特点和主要问题,并提出了进一步完善我国体育法的建议。     

The relationship between mechanical stiffness and athletic performance markers in sub-elite footballers

This study investigated the relationship between several measures of lower-body stiffness and physical performance variables in 22 sub-elite male football players (mean ± SD; 21.9 ± 1.5 yr; 1.79 ± 0.06 m; 72.2 ± 7.2 kg). The participants were assessed for individual muscle stiffness of the Rectus Femoris (RF), Biceps Femoris (BF) and Medial Gastrocnemius (MG) muscles and vertical stiffness (Kvert) was also assessed assessed running acceleration, maximal sprint speed, agility, vertical jumping and muscular strength. Pearson’s correlations quantified the relationships and participants were also separated into relatively stiff (SG) and compliant groups (CG) for each variable. When ranked by Kvert the SG exhibited superior performance during sprinting, agility, jumping and strength (p ≤ 0.05) and when ranked by RF stiffness, SG exhibited superior sprint, agility and drop jump performance (p ≤ 0.05), while MG and BF stiffness were not related to performance. Higher stiffness appears to be beneficial to athletic performance for football players and therefore it may be beneficial for practitioners working with athletes that are required to perform dynamic activities to consider the contribution of stiffness to athletic performance.     

Power,performance, and expectations in the dismissal of NBA coaches: A survival analysis study

Researchers focusing on coach dismissal often examine organizational performance as an antecedent; however, there has been minimal attention to the ways in which countervailing dimensions of power associated with coaches and ownership influence dismissal decisions, while still considering performance as well as expectations. To understand how power, performance and expectations affect coach dismissals, the authors examine the tenures of coaches in the North American-based National Basketball Association and use survival analysis to test a model of coach dismissals using 31 years of observations. The authors find that coach dismissal is a process influenced not only by team performance, but also expectations and a coach’s power that accrues from both structure and prestige. Additional findings suggest that expert power influences the likelihood of coach dismissal, but only after the coach has been in the job for several years. Finally, the authors found a non-linear relationship between performance and the probability of coach dismissal, suggesting that single events (i.e., wins or losses) have less influence on the probability of dismissal when performance is very poor or above average.     

Shoe collar height effect on athletic performance,ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.     

自我设限策略在体育运动中的运用及其对运动表现的影响

试图检验自我效能和自尊是否可以作为两种自我设限策略——声称式的和行为式的——预测指标,并且比较了两种策略和运动表现的关系。以体育学院篮球专业部分新生为研究对象,结果表明:声称式的自我设限策略和自尊显著负相关,而行为式的自我设限策略和自我效能显著负相关。运动表现和行为式的自我设限负相关,和声称式的自我设限不相关。研究结果表明两种自我设限策略和不同的影响因素相联系,并且对运动表现有不同的影响。     

浅析太极劲训练中的特点与方法

文章通过文献资料和练习方法中的体会,比较分析太极劲与一般体育力、太极松沉劲基础训练方法与一般体育放松训练方法的相似与不同,总结归纳出太极劲训练中的特点和方法,并通过大小,方向,作用点的训练步骤将太极劲的训练由繁化简,由难化易,使其更加科学化,易于大众掌握。     

Power,consent and resistance: an autoethnography of competitive rowing

This study builds upon existing socio-cultural work into sports coaching by probing the meanings and varieties of the shared coach–athlete experience. Specifically, the paper utilises an autoethnographic approach in an attempt to chart the complex and dynamic relationship that existed between me, the principal author, as a rowing coxswain and my coach during the preparation for a national rowing championship. Data were drawn from a training diary, emails (both sent and received) and memories during the six months I spent with Coach. The data are presented through three separate yet inter-related stories. Here, the plot of the tale hinges on the tension between my personal perceptions of effective coaching and those employed by Coach. The findings are principally theorised through Nyberg's and Giddens’ concepts of power and resistance, as a fruitful relationship between Coach and me (and the crew) soon turned into a dysfunctional one. The conclusion emphasises the importance of recognising the power-ridden nature of coaching and the value of the autoethnographic genre in exploring it.     

普通高校体育教师课程权力及其实现策略

通过文献资料法,对教师课程权力和普通高校体育教师课程权力的来源进行理论分析;为了合理有效运用教师的课程权力,提出普通高校体育课程教学中应制定与新纲要相配套的课程实施细则、创新教师专业发展的课程体制和提升教师课程素养等实现教师课程权力的策略。