Development and field validation of an omni-domain power-duration model

ABSTRACT

Purpose: To validate and compare a novel model based on the critical power (CP) concept that describes the entire domain of maximal mean power (MMP) data from cyclists.

Methods: An omni-domain power-duration (OmPD) model was derived whereby the rate of W? expenditure is bound by maximum sprint power and the power at prolonged durations declines from CP log-linearly. The three-parameter CP (3CP) and exponential (Exp) models were likewise extended with the log-linear decay function (Om3CP and OmExp). Each model bounds W? using a different nonconstant function, W?eff (effective W?). Models were fit to MMP data from nine cyclists who also completed four time-trials (TTs).

Results: The OmPD and Om3CP residuals (4 ± 1%) were smaller than the OmExp residuals (6 ± 2%; P < 0.001). W?eff predicted by the OmPD model was stable between 120–1,800 s, whereas it varied for the Om3CP and OmExp models. TT prediction errors were not different between models (7 ± 5%, 8 ± 5%, 7 ± 6%; P = 0.914).

Conclusion: The OmPD offers similar or superior goodness-of-fit and better theoretical properties compared to the other models, such that it best extends the CP concept to short-sprint and prolonged-endurance performance.     

To me,to you: How you say things matters for endurance performance

ABSTRACT

Self-talk enhances physical performance. Nothing is known however about the way that a subtle grammatical difference in self-talk, using first or second person pronouns, may effect performance. As second person self-talk supports self-regulation in non-exercise populations, we hypothesized that 10 km cycling time-trial performance would be superior following second versus first person self-talk. Using a randomized, counterbalanced, crossover design, sixteen physically active males (M_age = 21.99, SD = 3.04 years) completed a familiarization visit followed by a 10 km time-trial during two separate experimental visits using first and second person self-talk. A paired t-test revealed that second person self-talk generated significantly faster time-trial performance than first person self-talk (p = .014). This was reflected in a significantly greater power output throughout the time-trial when using second person self-talk (p = .03), despite RPE remaining similar between conditions (p = .75). This is the first evidence that strategically using grammatical pronouns when implementing self-talk can influence physical performance providing practitioners with a new aspect to consider when developing interventions. We discussed findings in the context of a self-distancing phenomenon induced by the use second person pronouns.     

从单向传播到一体化:体育组织与媒介关系形态研究

采用文献资料调研和逻辑分析法回顾了体育组织与媒介关系发展的历史,从两者相互交织的利益取向出发,将体育组织与媒介关系分为:媒介对体育及体育组织的介入期、体育组织与媒介关系稳定发展期和共生成熟期。研究结果认为,体育组织与媒介关系形态表现为单向传播关系、合作关系和共生关系;这3种关系形态不仅仅是纵向的、历史演变的结果,同时也是一种横向的、在当今社会也同时存在的关系形态;决定体育组织与媒介关系形态的因素包括体育制度与媒介制度、媒介传播力以及受众对媒体的依赖程度。     

从师徒到师生:教学关系转变后学校武术教育的时代之思

在国家需求高质量全面发展人才的背景下,必须深度省思历经百年学校武术教育质量难以让人满意的问题。以民国前后教学关系转变为切入点,深度分析师徒式教学关系与师生式教学关系的优缺点,经过对两者的教学主体、教学方式、教学方法、教学目的等方面进行分析,发现两种教学关系存在着巨大的互补性。研究最后指出:在充分地剖析与解读新时代的教学对象之后,可以将两种教学关系融合;适度提升教师在学生心目中的地位,可以有效保障优秀传统文化的传承;古今教学方法的融合运用,可以提高人才培养的质量。     

从师徒到师生:教学关系转变后学校武术教育的时代之思

在国家需求高质量全面发展人才的背景下，必须深度省思历经百年学校武术教育质量难以让人满意的问题。以民国前后教学关系转变为切入点，深度分析师徒式教学关系与师生式教学关系的优缺点，经过对两者的教学主体、教学方式、教学方法、教学目的等方面进行分析，发现两种教学关系存在着巨大的互补性。研究最后指出：在充分地剖析与解读新时代的教学对象之后，可以将两种教学关系融合；适度提升教师在学生心目中的地位，可以有效保障优秀传统文化的传承；古今教学方法的融合运用，可以提高人才培养的质量。     

Cognitive to physical performance: a conceptual model for the role of motor simulation in performance

ABSTRACT

Motor simulation (MS) interventions incorporating motor imagery (MI), and more recently action observation (AO), are readily accepted as effective interventions to enhance motor skill performance. Existing models in the MS literature fail to consider the entire spectrum of MS interventions, focusing on MI or AO alone. This paper examines the theoretical basis and current understanding of MS efficacy, and introduces a novel, conceptual, Motor Simulation and Performance Model (MSPM) representing the performance improvements predicted to be associated with engaging with MS across expertise levels. The MSPM also outlines the multiple factors which regulate the efficacy of MS interventions. Based on the available evidence, the model suggests that MI will have a greater relative effect on performance as expertise increases, AO will have a greater effect in low skilled compared to high skilled performers, and that combined AO and MI (AO?+?MI) will be more effective than either MI or AO in isolation. The MSPM also depicts the additive effect of physical practice in conjunction with MS interventions. The MSPM represents for the first time the relative effects of various methods of motor learning based on evidence provided by the existing literature. It also highlights areas of research requiring further attention.     

Mechanical power,thrust power and propelling efficiency: relationships with elite sprint swimming performance

The purpose of this study was to explore the relationships between mechanical power, thrust power, propelling efficiency and sprint performance in elite swimmers. Mechanical power was measured in 12 elite sprint male swimmers: (1) in the laboratory, by using a whole-body swimming ergometer (W'_TOT) and (2) in the pool, by measuring full tethered swimming force (F_T) and maximal swimming velocity (V_max): W'_T = F_T · V_max. Propelling efficiency (η_P) was estimated based on the “paddle wheel model” at V_max. V_max was 2.17 ± 0.06 m · s^?1, η_P was 0.39 ± 0.02, W'_T was 374 ± 62 W and W'_TOT was 941 ± 92 W. V_max was better related to W'_T (useful power output: R = 0.943, P < 0.001) than to W'_TOT (total power output: R = 0.744, P < 0.01) and this confirms the use of the full tethered test as a valid test to assess power propulsion in sprinters and to estimate swimming performance. The ratio W'_T/W'_TOT (0.40 ± 0.04) represents the fraction of total mechanical power that can be utilised in water (e.g., η_P) and was indeed the same as that estimated based on the “paddle wheel model”; this supports the use of this model to estimate η_P in swimming.     

建国以来认识和处理群众体育与竞技体育关系的历史启示

分析了建国后认识和处理群众体育与竞技体育在形态上、价值取向上的变化,提出了追求体育价值的同时,必须树立代价意识,防止对某一方面价值追求的过度膨胀,而不付出任何代价欲取得协调,则是不现实的。     

Understanding the track and field sprint start through a functional analysis of the external force features which contribute to higher levels of block phase performance

This study aimed to identify the continuous ground reaction force (GRF) features which contribute to higher levels of block phase performance. Twenty-three sprint-trained athletes completed starts from their preferred settings during which GRFs were recorded separately under each block. Continuous features of the magnitude and direction of the resultant GRF signals which explained 90% of the variation between the sprinters were identified. Each sprinter’s coefficient score for these continuous features was then input to a linear regression model to predict block phase performance (normalised external power). Four significant (p < 0.05) predictor features associated with GRF magnitude were identified; there were none associated with GRF direction. A feature associated with greater rear block GRF magnitudes from the onset of the push was the most important predictor (β = 1.185), followed by greater front block GRF magnitudes for the final three-quarters of the push (β = 0.791). Features which included a later rear block exit (β = 0.254) and greater front leg GRF magnitudes during the mid-push phase (β = 0.224) were also significant predictors. Sprint practitioners are encouraged, where possible, to consider the continuous magnitude of the GRFs produced throughout the block phase in addition to selected discrete values.     

Functional impact of emotions on athletic performance: Comparing the IZOF model and the directional perception approach

A plausible explanation for the ancient long jump records from Greek antiquity is sought on the basis of pictorial and written sources, and corroborated with practical tests. Ancient sources report that athletes jumped more than 15?m with weights in their hands, which enabled them to jump further than without these weights. It is proposed that the ancient Greek long jump was a continuous succession of five standing broad jumps, in which the landing phase of one jump was also the countermovement for the next jump. Four trained athletes jumped further with (14.64?±?0.76?m, range 13.64?–?15.63?m) than without weights (13.88?±?0.70?m, range 12.60?–?14.75?m; P = 0.001). These results show that this technique is executable, fits with ancient written and pictorial sources, and allows trained modern athletes to jump distances well over 15?m. The extra distance jumped when using weights may be due to changes in the position of the jumper's centre of mass at take-off and at landing, and an increase in take-off velocity stemming from several biomechanical mechanisms.     

男子三级跳远专项力量训练与弱爆发力特征的关系

通过对速度和爆发力素质差的三级跳远运动员高春冬采用特定的训练方案进行训练,使其专项成绩1a内提高0．8m,达到15．40m(国家一级运动员)的水平。特定的训练方案是以提高快速跳跃力量、发展退让肌群力量和专项耐力为目标,以不同的手段组合成4套训练方案,其针对性强,效果好。该方案适用于相近水平的三级跳远运动员。     

Observation interventions for motor skill learning and performance: an applied model for the use of observation

Using the 5 Ws and 1 H journalistic approach of Beveridge Mackie (2011), we reviewed the observation intervention research that targeted sport skills or daily movement tasks. Through this review, it became apparent that while there is much research that examines observation of a live or video (what), skilled model (who) for enhanced skill learning (why) in laboratory settings (where), there is a need for not only a wider scope of research, but also a deeper one. Following the review of literature, an applied model for the use of observation is advanced. Through this applied model, we propose that practitioners should first assess the observer's characteristics and the task characteristics for which any observation intervention is being created. The practitioner should then gain an understanding of the context and the desired outcomes of the learner and use this advance information to vary the characteristics of: (1) who is observed; (2) what is observed and what instructional features will accompany the intervention; (3) when it is observed; and (4) how the observed information should be delivered. Future research directions are also forwarded with regard to identified gaps in the literature.     

深根固柢, 长生久视之道———中国古代体育观给我们的启示

随着科学技术的进步,人们正在享受着社会进步带来的欢乐的同时,又面临着困扰我们生活的两大世界性难题:一是生态环境遭到空前破坏,南极臭氧层空洞不断扩大,全球变暖,森林面积急剧减少,土地荒漠化日趋严重,众多物种已经灭绝或面临灭绝,一些重要资源面临枯竭,飓风、台风越刮越多,越刮越大,……;二是不同文化冲突加剧,局部战争连年不断,恐怖活动在世界范围内蔓延,思想意识形态矛盾四伏,……。人们在寻求解决这些问题的方法与途径时,共同把目光投向了中国古老的东方哲学。大家惊喜地发现,中国古代先贤们提出的“天人合一”观与“和而不同”的哲…     

在教学中如何处理好掌握技能与发展能力的关系

技能与能力是学校体育教学任务中的重要内容，技能训练和能力培养过程具有不同特点。处理好技能训练和能力培养之间的关系，发挥两者优势，对提高教学效果能起到事半功倍的作用。     

建国初期中国体育对外关系的战略思考与路径选择

就建国初期中国体育对外关系的战略思考与路径选择进行讨论。结果认为:建国初期的体育对外关系,在坚持独立自主外交政策的原则下,注意围绕"一边倒"的国家外交战略,通过不同的具体路径选择,在服从和服务于国家外交大政方针的同时,较好地打开了新中国体育对外发展的新局面,并为后来新中国体育事业的全面发展奠定了较好的基础。     

Sport participation and its association with social and psychological factors known to predict substance use and abuse among youth: A scoping review of the literature

ABSTRACT

This article presents the results of a scoping review of the sport literature (2000–2014) on psychological and social outcomes relevant to youth alcohol and illicit drug use. Prior reviews report that sport is related to increased alcohol use and reduced illicit drug use among youth, yet provide little guidance regarding the mechanisms that can explain this relationship. We reviewed the literature on sport participation and psychological and social outcomes to identify factors that could help explain this link. Psychological and social factors were selected as they play a paramount role in understanding youth alcohol and drug use. Fifty-nine articles were identified and included in the review. The literature generally supported connections between sport and positive psychological and social outcomes, including self-esteem, self-regulation, general life skills, and pro-social behaviour. Yet limitations in the methods and measures limit the ability to draw conclusions from the literature. In addition, the diversity of youth and sport was generally ignored in the literature. This article suggests a number of directions for future research that might improve our understanding of how sport impacts psychological and social outcomes along with alcohol and illicit drug use.     

Self-belief does make a difference: A reciprocal effects model of the causal ordering of physical self-concept and gymnastics performance

Abstract

A large body of research in support of the reciprocal effects model of causal ordering demonstrates that prior academic self-concept predicts subsequent academic achievement beyond what can be explained in terms of prior achievement. Here we evaluate the generalizability of this support for the reciprocal effects model to a physical activity context in which achievement is reflected in gymnastics skills on a standardized gymnastics performance test evaluated by expert judges. Based on the responses of 376 adolescents collected at the start (T1) and end (T2) of a gymnastics training programme, there is support for a reciprocal effects model in which there are significant paths leading from both T1 gymnastics self-concept to T2 gymnastics skills and from T1 gymnastics skills to T2 self-concept. Although there were gender and age effects (girls and older participants had better gymnastics skills, boys had higher self-concepts), multiple group structural equation models indicated that support for the reciprocal effects model generalized over responses by boys and girls. In summary, self-concept and performance are both determinants and consequences of each other.     

Coaching competency and satisfaction with the coach: A multi-level structural equation model

Abstract

The purpose of this initial predictive validity study was to determine the ability of measures derived from the Athletes' Perceptions of Coaching Competency Scale II – High School Teams (APCCS II-HST) to predict satisfaction with the head coach. Specification of the statistical model was informed by the mediational model of coach–athlete interactions. The technical quality of the satisfaction measure was evaluated before testing the predictive validity of the coaching competency measures. Data were collected from athletes of seven sports. Athlete observations (N = 748) were clustered within teams (G = 74). Multi-group confirmatory factor analyses (CFA) provided evidence for factorial invariance of a reduced version of the satisfaction measure by athlete gender. Multi-level CFA provided evidence of model–data consistency for a reduced version of the satisfaction measure. Multi-level structural equation modelling provided evidence for the ability of latent coaching competency to positively predict latent satisfaction at both the athlete level (technique competency and motivation competency) and the team level (coaching competency) and for close model–data fit. Implications of this study include: that the APCCS II-HST should be viewed as a replacement for the Coaching Competency Scale when the intended population is appropriate; a preliminary multi-level measurement model for satisfaction with one's coach that should be considered as a potential starting point in subsequent studies; and empirical support for a key relationship proposed in the mediational model of coach–athlete interactions.     

Perceptual-cognitive skill training and its transfer to expert performance in the field: Future research directions

Abstract

Perceptual-cognitive skills training provides a potentially valuable method for training athletes on key skills, such as anticipation and decision-making. It can be used when athletes are unable to physically train or are unable to experience repeated key situations from their sport. In this article, we review research on perceptual-cognitive skills training and describe future research areas focusing on a number of key theories and principles. The main aim of any training intervention should be the efficacy of retention and transfer of learning from training to field situations, which should be the key consideration when designing the representative tasks used in perceptual-cognitive skills training. We review the principles that seek to create practice tasks that replicate those found in the field, so as to increase the amount of transfer that occurs. These principles are perception–action coupling, the contextual interference effect and contextual information, which suggest there should be a high level of similarity between training and real-life performance when designing perceptual-cognitive skills training. In the final section, we discuss the transfer of retained skill acquisition from perceptual-cognitive skills training to field performance, which we suggest to be the key area for future research in this area.     

Facebook and sport education: mirroring the model at home to promote parental involvement

ABSTRACT

Social networks had become so important that they constitute a way of life for many individuals, and Facebook is probably the most popular one. Society has become totally connected, but classrooms still remain rather isolated. The goal of the study was to extend the Sport Education Model (SEM) through a social network, Facebook, to promote parental involvement, assessing its impact at home. 41 parents of 49 grade 12th secondary education students agreed to participate (39?57 years): 14 fathers and 27 mothers. The vast majority of participating parents that included information about their socio-economic and educational background considered themselves medium level (11 out of 13). Unfortunately, most parents did not provide this type of information (69.30%). An AcroGymnastics learning unit was implemented using the SEM during 16 sessions. All Facebook activity was recorded by the site, and semi-structured interviews were used to obtain data directly from the parents. Quantitative data was analysed using Gytrics, while MAXQDA 11 helped with qualitative data management. Quantitative results showed that the Facebook group had a notable effect in parents’ involvement: 42.26% joined (67% mothers), 100% reacted, 70.47% published content, 48.69% uploaded a picture/video, 503 posts, 14,528 hits, and 2025 reactions: 1912 likes and 113 comments. Themes derived from the analysis of the qualitative data reinforced the idea that Facebook helped promote parental participation: involvement, affiliation and learning, and some SEM features at home: affiliation, festive atmosphere and participation. Finally, a change in the PE status was also observed among parents. In conclusion, the combination Facebook-SEM had a notable positive effect on parental involvement, especially among mothers of medium socio-economic background. The number and type of activities posted by the administrator seemed to be a key element to positively integrate Facebook in education.