基于主客场赛季训练特点谈篮球比赛及其训练模式

运用文献资料法,结合自身实践经历讨论篮球主客场赛季训练的三大特点,分别从篮球比赛训练内容和手段、负荷特点、调控竞技状态及恢复训练四方面重点分析篮球主客场赛季训练模式,为篮球比赛和训练提供参考。     

Analysis of lower limb internal kinetics and electromyography in elite race walking

Abstract

The aim of this study was to analyse lower limb joint moments, powers and electromyography patterns in elite race walking. Twenty international male and female race walkers performed at their competitive pace in a laboratory setting. The collection of ground reaction forces (1000 Hz) was synchronised with two-dimensional high-speed videography (100 Hz) and electromyography of seven lower limb muscles (1000 Hz). As well as measuring key performance variables such as speed and stride length, normalised joint moments and powers were calculated. The rule in race walking which requires the knee to be extended from initial contact to midstance effectively made the knee redundant during stance with regard to energy generation. Instead, the leg functioned as a rigid lever which affected the role of the hip and ankle joints. The main contributors to energy generation were the hip extensors during late swing and early stance, and the ankle plantarflexors during late stance. The restricted functioning of the knee during stance meant that the importance of the swing leg in contributing to forward momentum was increased. The knee flexors underwent a phase of great energy absorption during the swing phase and this could increase the risk of injury to the hamstring muscles.     

以辅导员为载体推动思想政治教育精细化

思想政治教育精细化是当前做好大学生思想政治工作的要求。高校辅导员作为对学生进行思想政治教育工作的一线工作者,是最直接的落实者和推动者,他们对精细化工作的执行程度直接决定了思想政治教育精细化的效果。因此,新形势下做好大学生的思想政治教育精细化工作,要以辅导员为载体,从辅导员自身的专业素养、规范的工作程序、细致的对象分析、具体的工作执行四方面来进行努力和探索。     

Lower limb joint kinetics during the first stance phase in athletics sprinting: three elite athlete case studies

Abstract

This study analysed the first stance phase joint kinetics of three elite sprinters to improve the understanding of technique and investigate how individual differences in technique could influence the resulting levels of performance. Force (1000 Hz) and video (200 Hz) data were collected and resultant moments, power and work at the stance leg metatarsal-phalangeal (MTP), ankle, knee and hip joints were calculated. The MTP and ankle joints both exhibited resultant plantarflexor moments throughout stance. Whilst the ankle joint generated up to four times more energy than it absorbed, the MTP joint was primarily an energy absorber. Knee extensor resultant moments and power were produced throughout the majority of stance, and the best-performing sprinter generated double and four times the amount of knee joint energy compared to the other two sprinters. The hip joint extended throughout stance. Positive hip extensor energy was generated during early stance before energy was absorbed at the hip as the resultant moment became flexor-dominant towards toe-off. The generation of energy at the ankle appears to be of greater importance than in later phases of a sprint, whilst knee joint energy generation may be vital for early acceleration and is potentially facilitated by favourable kinematics at touchdown.     

Causal attribution and emotion in the days following competition

Abstract

We examined the extent to which attributions are consistent in the days following competition and how attributions made immediately after competition may influence the temporal patterning of emotions experienced in response to competition. A sample of 60 adult female golfers completed measures of performance satisfaction, causal attribution, and emotion immediately after competition, 5 h after competition, and 2 days after competition. Repeated-measures multivariate analysis of covariance indicated that attributions did not change over this period. Emotions showed a significant decrease in intensity over the 5-h post-competition period. Regression analyses indicated that changes in anger and dejection were more likely in the case of less successful performances. For anger, attributions moderated this level of change. Golfers experienced anger for a longer period when they identified the cause of poor performance as stable rather than unstable. Thus, in the present sample although attributions did not change over 2 days, the longevity of anger depended on the attributions made immediately after competition.     

Exploring the relationship between hope and burnout in competitive sport

Abstract

Researchers have postulated that hope may be an important factor associated with burnout. Consistent with hope theory contentions, low-hope individuals may be susceptible to burnout because they are prone to experience goal blockage, frustration, and negative affect, all of which likely increase the risk of burnout. We examined the relationship between hope and athlete burnout among 178 competitive athletes (63 females and 115 males) aged 15–20 years. Hope was significantly and negatively correlated with all three burnout subscales: emotional/physical exhaustion, a reduced sense of accomplishment, and sport devaluation. Moreover, results of a multivariate analysis of variance showed that low-hope athletes scored significantly higher than medium- and high-hope athletes on all three burnout dimensions. Finally, results revealed that agency thinking was a significant predictor of all burnout dimensions. Frustration over unmet goals and a perceived lack of agency, a characteristic of low-hope athletes, might pose a risk factor in athlete burnout, whereas being able to maintain hope appears to be associated with health and well-being.     

Analysis of Stroke Organization in the Backstroke as a Function of Skill

Abstract

This study investigated the effects of three different amounts of practice in combination with two types of variable practice conditions upon schema development. Seventy-two subjects were administered either 6, 18, or 36 trials while learning to move to either one- or three-criteria goals on the linear positioning task. Subjects then had 18 no-KR (knowledge of results) trials to produce a novel response. The statistical analysis revealed a significant three-way interaction for absolute error while no significant main or interaction effects existed for constant or variable error. Analysis of the simple main effects showed that the various amounts of practice produced similar performances for the subjects learning to move to only one criterion goal. For the subjects learning to move to three criteria goals during initial practice, the amount of practice provided was a significant factor in the accuracy and strength of the motor schema. Partial support is presented for schema theory.     

Accelerometer and GPS Data to Analyze Built Environments and Physical Activity

ABSTRACT

Purpose: Most built environment studies have quantified characteristics of the areas around participants’ homes. However, the environmental exposures for physical activity (PA) are spatially dynamic rather than static. Thus, merged accelerometer and global positioning system (GPS) data were utilized to estimate associations between the built environment and PA among adults. Methods: Participants (N = 142) were recruited on trails in Massachusetts and wore an accelerometer and GPS unit for 1–4 days. Two binary outcomes were created: moderate-to-vigorous PA (MVPA vs. light PA-to-sedentary); and light-to-vigorous PA (LVPA vs. sedentary). Five built environment variables were created within 50-meter buffers around GPS points: population density, street density, land use mix (LUM), greenness, and walkability index. Generalized linear mixed models were fit to examine associations between environmental variables and both outcomes, adjusting for demographic covariates. Results: Overall, in the fully adjusted models, greenness was positively associated with MVPA and LVPA (odds ratios [ORs] = 1.15, 95% confidence interval [CI] = 1.03, 1.30 and 1.25, 95% CI = 1.12, 1.41, respectively). In contrast, street density and LUM were negatively associated with MVPA (ORs = 0.69, 95% CI = 0.67, 0.71 and 0.87, 95% CI = 0.78, 0.97, respectively) and LVPA (ORs = 0.79, 95% CI = 0.77, 0.81 and 0.81, 95% CI = 0.74, 0.90, respectively). Negative associations of population density and walkability with both outcomes reached statistical significance, yet the effect sizes were small. Conclusions: Concurrent monitoring of activity with accelerometers and GPS units allowed us to investigate relationships between objectively measured built environment around GPS points and minute-by-minute PA. Negative relationships between street density and LUM and PA contrast evidence from most built environment studies in adults. However, direct comparisons should be made with caution since most previous studies have focused on spatially fixed buffers around home locations, rather than the precise locations where PA occurs.     

The Origins of Football Debate: Comments on Adrian Harvey's Historiography

This article is intended as a reply to Adrian Harvey's recent historiography of football in which he continues to distort the story of the initial development of the game. It not only refutes the revisionist hypothesis of an influential football sub-culture based around public houses but also offers an alternative explanation of the game's past, largely based on the influence of ex-public schoolboys and former university undergraduates. It seeks to push the debate a step further by robustly re-asserting the meagre nature of the revisionist evidence in addition to Adrian Harvey's poor scholarship.     

The Health Risks of Doping during the Cold War: A Comparative Analysis of the Two Sides of the Iron Curtain

This article compares East Germany's Cold War-era approach to doping to that of the USA's in terms of their respective impacts on medical risk. Although deserving of criticism on many levels, the GDR doping programme featured a number of safeguards designed to minimise medical dangers. Unlike their East German counterparts, American governmental units were not directly involved in the administration of performance-enhancing substances. The US approach to doping was not ideal in terms of medical risk, however. As a result of the country's regulatory approach to doping, the country's athletes frequently turned to black market sources for doping agents. It was also relatively common for American athletes to use performance-enhancing drugs without the benefit of medical supervision. The US approach to doping was in these ways inferior to that of East Germany's on the subject of medical risk.