Modelling mood states in athletic performance

The ability to recognize patterns of play is fundamental to performance in team sports. While typically assumed to be domain-specific, pattern recognition skills may transfer from one sport to another if similarities exist in the perceptual features and their relations and/or the strategies used to encode and retrieve relevant information. A transfer paradigm was employed to compare skilled and less skilled soccer, field hockey and volleyball players' pattern recognition skills. Participants viewed structured and unstructured action sequences from each sport, half of which were randomly represented with clips not previously seen. The task was to identify previously viewed action sequences quickly and accurately. Transfer of pattern recognition skill was dependent on the participant's skill, sport practised, nature of the task and degree of structure. The skilled soccer and hockey players were quicker than the skilled volleyball players at recognizing structured soccer and hockey action sequences. Performance differences were not observed on the structured volleyball trials between the skilled soccer, field hockey and volleyball players. The skilled field hockey and soccer players were able to transfer perceptual information or strategies between their respective sports. The less skilled participants' results were less clear. Implications for domain-specific expertise, transfer and diversity across domains are discussed.     

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), date 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.     

The effect of induced mood states on performance profile areas of perceived need

The performance profile technique is now widely used by a range of sports scientists, usually as the first step in implementing a training programme. The aim of this study was to examine the effect of altered mood states on areas of perceived need for an individual identified by the performance profile. Sixty-seven university sports science students (30 females, 37 males) participated in the study. They completed their performance profile and a shortened version of the Bi-polar Profile of Mood States before and after four separate mood manipulation treatments (happy, sad, neutral, control). The participants were allocated at random to one of four groups and completed the treatments in a counterbalanced order. Mood manipulation checks identified that both the happy and sad manipulations were successful. Profile areas of perceived need, identified through discrepancies in an individual's perceptions of ideal and current state, were not affected by the sad and neutral manipulations or by the control condition. However, areas of perceived need were significantly lower after the happy mood manipulation than before the treatment. Our results show that asking individuals to complete their profiles when in a happy mood state is likely to affect judgements and result in an underestimation of perceived need for improvement.     

竞技表现的特征

运动员的竞技能力是竞技对抗的基础,而临场竞技表现可以直接决定最终的胜负.把握竞技表现的特征对竞技实践有重要的意义.竞技表现的特征主要有:稳定性、波动性、相对性、不可预测性、相对可控性等.     

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.     

Mood responses to athletic performance in extreme environments

Competition at elite level can require athletes to perform optimally in extreme environmental conditions. This review focuses on mood responses in such conditions and proposes practical guidelines for those working with athletes. Different environments are considered, including altitude and extreme heat and cold. Performing in extreme heat, cold or at altitude can produce a stress response characterized by increased negative mood and relatively poor performance. Positive adaptations to extreme conditions can be accelerated, but the rate of adaptation appears to be highly individualized. Monitoring mood responses to training under normal conditions provides a basis for identifying the psychological effects of extreme conditions. It is suggested that practitioners carefully monitor the interplay between vigour, fatigue and depressed mood. Reductions in vigour and increases in fatigue are normal responses to hard training, but other aspects of mood disturbance, especially symptoms of depressed mood--however small--may be indicative of a maladaptive response, and practitioners should consider intervening when such symptoms first appear.     

Mood responses to athletic performance in extreme environments

Competition at elite level can require athletes to perform optimally in extreme environmental conditions. This review focuses on mood responses in such conditions and proposes practical guidelines for those working with athletes. Different environments are considered, including altitude and extreme heat and cold. Performing in extreme heat, cold or at altitude can produce a stress response characterized by increased negative mood and relatively poor performance. Positive adaptations to extreme conditions can be accelerated, but the rate of adaptation appears to be highly individualized. Monitoring mood responses to training under normal conditions provides a basis for identifying the psychological effects of extreme conditions. It is suggested that practitioners carefully monitor the interplay between vigour, fatigue and depressed mood. Reductions in vigour and increases in fatigue are normal responses to hard training, but other aspects of mood disturbance, especially symptoms of depressed mood - however small - may be indicative of a maladaptive response, and practitioners should consider intervening when such symptoms first appear.     

Joint kinetic determinants of starting block performance in athletic sprinting

The aim of this study was to explore the relationships between lower limb joint kinetics, external force production and starting block performance (normalised average horizontal power, NAHP). Seventeen male sprinters (100 m PB, 10.67 ± 0.32 s) performed maximal block starts from instrumented starting blocks (1000 Hz) whilst 3D kinematics (250 Hz) were also recorded during the block phase. Ankle, knee and hip resultant joint moment and power were calculated at the rear and front leg using inverse dynamics. Average horizontal force applied to the front (r = 0.46) and rear (r = 0.44) block explained 86% of the variance in NAHP. At the joint level, many “very likely” to “almost certain” relationships (r = 0.57 to 0.83) were found between joint kinetic data and the magnitude of horizontal force applied to each block although stepwise multiple regression revealed that 55% of the variance in NAHP was accounted for by rear ankle moment, front hip moment and front knee power. The current study provides novel insight into starting block performance and the relationships between lower limb joint kinetic and external kinetic data that can help inform physical and technical training practices for this skill.     

山东省女子长跑项目运动成绩演变评析

选取1984-2011年期间山东女子长跑优秀运动员参加全运会和全国性以及国际比赛最好成绩的数据,以1984-2008年共五届奥运会及1983年-2009年共7届全运会中女子长跑项目冠军的运动成绩作为参照进行统计分析,找出山东女子长跑运动成绩的变化规律及影响因素,以期为田径长跑项目的基础性研究提供参考。     

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.     

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.     

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 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.     

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.     

Relationships between muscle fibre characteristics and physical performance capacity in trained athletic boys

The relationships between muscle fibre characteristics and the physical performance capacity of trained athletic boys (aged 11-13 years) were studied over 2 days. The subjects were divided into two groups according to muscle fibre distribution. The 'fast' group (FG) comprised 10 subjects (sprinters, weightlifters, tennis players) with more than 50% fast-twitch fibres (type II), and the 'slow' group (SG) comprised 8 subjects (endurance runners, tennis players, one weightlifter) with more than 50% slow-twitch fibres (type I) in their vastus lateralis muscle. The 'fast' group had 59.2 +/- 6.3% and the 'slow' group had 39.4 +/- 9.8% type II fibres. Other clear differences (P less than 0.05-0.01) between the groups were observed as regards reaction time, rate of force development and rise of the body's centre of gravity in the squatting jump. For these variables, the 'fast' group was superior to the 'slow' group. Muscle fibre distribution (% type II) correlated (P less than 0.05-0.01) negatively with reaction time. Muscle fibre area (% type II) correlated negatively with reaction time (P less than 0.05-0.001) and positively with chronological age (P less than 0.05) height (P less than 0.05), mass (P less than 0.001), serum testosterone (P less than 0.05), force production (P less than 0.05-0.01) and blood lactate (P less than 0.05) in the 60-s maximal anaerobic test. There were no significant correlations between muscle fibre characteristics and maximal oxygen uptake. The present study assumes that heredity partly affects the selection of sporting event. Growth, development and training are associated with muscle fibre area, which affects the physical performance capacity of the neuromuscular system in trained young boys.     

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.     

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。     

Redistributing load using wearable resistance during power clean training improves athletic performance

A popular method to improve athletic performance and lower body power is to train with wearable resistance (WR), for example, weighted vests. However, it is currently unknown what training effect this loading method has on full-body explosive movements such as the power clean. The purpose of this study was to determine what effects WR equivalent to 12% body mass (BM) had on the power clean and countermovement jump (CMJ) performance. Sixteen male subjects (age: 23.2?±?2.7 years; BM: 90.5?±?10.3?kg) were randomly assigned to five weeks of traditional (TR) power clean training or training with 12% BM redistributed from the bar to the body using WR. Variables of interest included pre and post CMJ height, power clean one repetition maximum (1RM), peak ground reaction force, power output (PO), and several bar path kinematic variables across loads at 50%, 70%, and 90% of 1RM. The main findings were that WR training: (1) increased CMJ height (8.7%; ES?=?0.53) and 1RM power clean (4.2%; ES?=?0.2) as compared to the TR group (CMJ height?=??1.4%; 1RM power clean?=?1.8%); (2) increased PO across all 1RM loads (ES?=?0.33–0.62); (3) increased barbell velocity at 90% 1RM (3.5%; ES?=?0.74) as compared to the TR group (?4.3%); and (4) several bar path kinematic variables improved at 70% and 90% 1RM loads. WR power clean training with 12% BM can positively influence power clean ability and CMJ performance, as well as improve technique factors.     

Explosive force production during isometric squats correlates with athletic performance in rugby union players

Abstract

This study investigated the association between explosive force production during isometric squats and athletic performance (sprint time and countermovement jump height). Sprint time (5 and 20 m) and jump height were recorded in 18 male elite-standard varsity rugby union players. Participants also completed a series of maximal- and explosive-isometric squats to measure maximal force and explosive force at 50-ms intervals up to 250 ms from force onset. Sprint performance was related to early phase (≤100 ms) explosive force normalised to maximal force (5 m, r = ?0.63, P = 0.005; and 20 m, r = ?0.54, P = 0.020), but jump height was related to later phase (>100 ms) absolute explosive force (0.51 < r < 0.61; 0.006 < P < 0.035). When participants were separated for 5-m sprint time (< or ≥ 1s), the faster group had greater normalised explosive force in the first 150 ms of explosive-isometric squats (33–67%; 0.001 < P < 0.017). The results suggest that explosive force production during isometric squats was associated with athletic performance. Specifically, sprint performance was most strongly related to the proportion of maximal force achieved in the initial phase of explosive-isometric squats, whilst jump height was most strongly related to absolute force in the later phase of the explosive-isometric squats.