Book Review     

F. Colloud  P. Bahuaud  N. Doriot  S. Champely  L. Chèze 《Journal of sports sciences》2013,31(5):479-480

Abstract

The mechanical responses (i.e. external contact forces and external power) of 25 elite rowers to a race-pace rowing protocol were investigated on the traditional fixed stretcher mechanism and the more recently introduced free-floating stretcher mechanism rowing ergometers. Using a Rowperfect rowing ergometer for both conditions, external contact forces at the handle, stretcher and sliding seat, as well as the displacements of the handle and stretcher, were recorded. The external power was calculated as the product of the force and velocity data from both the handle and stretcher. Significant differences (P < 0.05) between the two conditions for each mechanical parameter were observed. The fixed condition showed larger maximum values for forces and external power and average power throughout the rowing cycle. Moreover, rowing with the fixed mechanism generated higher inertial forces during the transition between the propulsion and recovery phases, especially at the catch of the cycle. The results suggest that: (i) muscular coordination may differ according to the stretcher mechanism used, which could have an impact on the physiological adaptations of muscles; and (ii) the free-floating mechanism may induce lower catch and maximum values for net joint forces and net joint moments that could decrease the risk of injury.  相似文献   

Altitude and endurance training     

Heikki Rusko  Heikki Tikkanen  Juha Peltonen 《Journal of sports sciences》2013,31(10):928-945

The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (<2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is >12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.  相似文献   

Feasibility of eyes open alpha power training for mental enhancement in elite gymnasts     

Marian K. J. Dekker  Berber R. Van den Berg  Ad J. M. Denissen  Margriet M. Sitskoorn 《Journal of sports sciences》2013,31(16):1550-1560

Abstract

This study focuses on a novel, easy to use and instruction-less method for mental training in athletes. Previous findings suggest that particular mental capacities are needed for achieving peak performance; including attentional control, focus, relaxation and positive affect. Electroencephalography (EEG) alpha brain activity has been associated with neural inhibition during processes of selective attention, for improving efficiency in information processing. Here we hypothesised that eyes open alpha power training by music teaches athletes to (1) learn to self-regulate their brain activity, and (2) learn to increase their baseline alpha power, herewith improving mental capacities such as focusing the allocation of attention. The study was double-blind and placebo-controlled. Twelve elite gymnasts were either given eyes open alpha power training or random beta power training (controls). Results indicate small improvements in sleep quality, mental and physical shape. In our first attempt at getting a grip on mental capacities in athletes, we think this novel training method can be promising. Because gymnastics is one of the most mentally demanding sports, we value even small benefits for the athlete and consider them indicative for future research.  相似文献   

Psychological resilience in sport performers: a review of stressors and protective factors     

Mustafa Sarkar  David Fletcher 《Journal of sports sciences》2013,31(15):1419-1434

Abstract

Psychological resilience is important in sport because athletes must utilise and optimise a range of mental qualities to withstand the pressures that they experience. In this article, we discuss psychological resilience in sport performers via a review of the stressors athletes encounter and the protective factors that help them withstand these demands. It is hoped that synthesising what is known in these areas will help researchers gain a deeper profundity of resilience in sport, and also provide a rigorous and robust foundation for the development of a sport-specific measure of resilience. With these points in mind, we divided the narrative into two main sections. In the first section, we review the different types of stressors encountered by sport performers under three main categories: competitive, organisational and personal. Based on our recent research examining psychological resilience in Olympics champions, in the second section we discuss the five main families of psychological factors (viz. positive personality, motivation, confidence, focus, perceived social support) that protect the best athletes from the potential negative effect of stressors. It is anticipated that this review will help sport psychology researchers examine the interplay between stressors and protective factors, which will, in turn, focus the analytical lens on the processes underlying psychological resilience in athletes.  相似文献   

Does athletic training in volleyball modulate the components of visual evoked potentials? A preliminary investigation     

Teresa Zwierko  Wojciech Lubiński  Piotr Lesiakowski  Hanna Steciuk  Leszek Piasecki  Justyna Krzepota 《Journal of sports sciences》2013,31(16):1519-1528

Abstract

This longitudinal study investigated visual evoked potentials (VEPs) in 11 young female volleyball players who participated in extensive training for 2 years. The control group consisted of 7 age-matched female students who were not involved in any regular sports activity. Recordings of VEPs were performed twice: baseline recording (i.e., before training began) and after 2 years of systematic, volleyball-specific athletic training. The effect of athletic training on visual signal conductivity was assessed by recording the latency of N75, P100 and N135 components of the VEPs waveform. Extensive experience with volleyball training reduced signal conductivity time through visual pathway. Specifically, the latency of P100 was reduced on average by 2.2 ms during binocular viewing. Moreover, athletes had reduced N75 latency (difference of 3.3 ms) for visual stimuli that generated greater response from peripheral retina. These results indicate that sport training can affect very early sensory processing in athletes.  相似文献   

Self-Confidence as a Mediator of the Relationship Between Competitive Anxiety Intensity and Interpretation     

Stephen D. Mellalieu  Richard Neil  Sheldon Hanton 《Research quarterly for exercise and sport》2013,84(2):263-270

The aim of this study was to examine whether self-confidence mediated the relationship between competitive anxiety intensity and direction. Elite (n = 102) and nonelite (n = 144) participants completed the self-confidence subscale of the Competitive Trait Anxiety Inventory-2 and the worry and somatic subscales from the Sport Anxiety Scale. Consistent with procedures recommended by Baron and Kenny (1986), linear regression analyses were used. The findings for elite athletes revealed worry intensity to significantly predict self-confidence and worry direction. However, when self-confidence was controlled, worry intensity did not predict worry direction over that which was significantly predicted by self-confidence. Within the analysis for somatic symptoms, only self-confidence was found to predict somatic symptom direction. For the nonelite athletes, worry and somatic symptom intensity predicted both self-confidence and direction, and direction when self-confidence was controlled. The findings for the elite athletes suggest self-confidence mediates the relationship between performers' worry symptoms and subsequent directional interpretations. However, the findings suggest that high levels of self-confidence and low symptom intensity are needed for nonelite athletes to demonstrate a less debilitative interpretation.  相似文献   

Comparisons of physical characteristics and performances among female collegiate rowers     

Rebecca A. Battista  James M. Pivarnik  Gail M. Dummer  Norm Sauer  Robert M. Malina 《Journal of sports sciences》2013,31(6):651-657

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Motion analysis of match-play in elite U12 to U16 age-group soccer players     

Jamie A. Harley  Christopher A. Barnes  Matthew Portas  Ric Lovell  Stephen Barrett  Darren Paul 《Journal of sports sciences》2013,31(13):1391-1397

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Physiological characteristics of elite and sub-elite badminton players     

Cheong Hwa Ooi  Albert Tan  Azwari Ahmad  Kien Weng Kwong  Ruji Sompong  Khairul Aswadi Mohd Ghazali 《Journal of sports sciences》2013,31(14):1591-1599

Abstract

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO_2max 56.9 ml · kg^?1 · min^?1 (s = 3.7) and 59.5 ml · kg^?1 · min^?1 (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.  相似文献   

Experiential knowledge of expert coaches can help identify informational constraints on performance of dynamic interceptive actions     

Daniel Greenwood  Keith Davids  Ian Renshaw 《Journal of sports sciences》2013,31(4):328-335

Abstract

Coordination of dynamic interceptive movements is predicated on cyclical relations between an individual’s actions and information sources from the performance environment. To identify dynamic informational constraints, which are interwoven with individual and task constraints, coaches’ experiential knowledge provides a complementary source to support empirical understanding of performance in sport. In this study, 15 expert coaches from 3 sports (track and field, gymnastics and cricket) participated in a semi-structured interview process to identify potential informational constraints which they perceived to regulate action during run-up performance. Expert coaches’ experiential knowledge revealed multiple information sources which may constrain performance adaptations in such locomotor pointing tasks. In addition to the locomotor pointing target, coaches’ knowledge highlighted two other key informational constraints: vertical reference points located near the locomotor pointing target and a check mark located prior to the locomotor pointing target. This study highlights opportunities for broadening the understanding of perception and action coupling processes, and the identified information sources warrant further empirical investigation as potential constraints on athletic performance. Integration of experiential knowledge of expert coaches with theoretically driven empirical knowledge represents a promising avenue to drive future applied science research and pedagogical practice.  相似文献