Dehydration and sodium deficit during indoor practice in elite European male team players

Abstract

Aspects of team players' performance are negatively affected when ~ 2% body mass is lost by perspiration. Although such dehydration is likely reached during summer practice in outdoors sports, it is unclear if such dehydration is achieved during the practice of indoor sports. We assessed the fluid and electrolyte deficits of elite team players during practice for the following indoor sports: indoor soccer (n=9), basketball (n=11), volleyball (n=10), and handball (n=13). Morning hydration status was estimated by measuring urine specific gravity. Sweat rate was calculated from body mass changes and fluid intake. Sweat sodium concentration from the forearm was used to estimate whole-body sodium losses. Over 91% of the players were moderately hypohydrated (urine specific gravity>1.020) at waking 3 h before practice. Indoor soccer players sweated at a higher rate (1.8 litres · h^?1) than volleyball and handball players (1.2 and 1.1 litres · h^?1, respectively; P<0.05), whereas sweat rate was not different between basketball players (1.5 litres · h^?1) and the other team sport players (P>0.05). In average, 62±13% of sweat losses were replaced and teams' body mass loss did not exceed 1.2±0.3%. Sodium losses were similar among teams, averaging 1.2±0.2 g. The exercise fluid replacement habits of professional indoor team players are adequate to prevent 2% dehydration. However, most players could benefit from increasing fluid intake between workouts to offset the high prevalence of morning hypohydration.     

Perceived distributed effort in team ball sports

Abstract

In this study, we explored the multifaceted concept of perceived mental and physical effort in team sport contexts where athletes must invest individual and shared efforts to reach a common goal. Semi-structured interviews were conducted with a convenience sample of 15 Catalan professional coaches (3 women and 12 men, 3 each from the following sports: volleyball, basketball, handball, soccer, and water polo) to gain their views of three perceived effort-related dimensions: physical, psychological, and tactical. From a theoretical thematic analysis, it was found that the perception of effort is closely related to how effort is distributed within the team. Moreover, coaches viewed physical effort in relation to the frequency and intensity of the players’ involvement in the game. They identified psychological effort in situations where players pay attention to proper cues, and manage emotions under difficult circumstances. Tactical effort addressed the decision-making process of players and how they fulfilled their roles while taking into account the actions of their teammates and opponents. Based on these findings, a model of perceived distributed effort was developed, which delineates the elements that compose each of the aforementioned dimensions. Implications of perceived distributed effort in team coordination and shared mental models are discussed.     

篮、排球队员肩关节肌力的对比研究

对比分析篮、排球专项队员肩关节肌肉力量特点,结合篮球、排球专项技术特点指导专项体能训练并预防运动损伤。结论:篮球队员左侧肩关节屈肌力量较排球队员大;排球队员右侧肩关节伸肌爆发力较篮球队员要好;两专项队员屈/伸和内旋/外旋力量比率偏小,应注意肩关节肌肉力量均衡发展,尤其是肩关节内外旋肌肉。     

The relationship between functional potential and field performance in elite female wheelchair basketball players

The functional classification system for wheelchair basketball is based on an analysis of the players' functional resources through field-testing and game observation. Under this system, players are assigned a score of 1 to 4.5. The aim of this study was to determine if the wheelchair basketball player classification system reflects the existing differences in performance of elite female players. During the World Championship for Wheelchair Basketball in Sydney 1998, eight teams were videotaped for three 40-min games for a total of 120 min per team. Fifty-nine female players (Class I [1 and 1.5 points] n=12; Class II [2 and 2.5 points] n=20; Class III [3 and 3.5 points] n=13; Class IV [4 and 4.5 points] n=14) were retained for a detailed performance analysis by means of the Comprehensive Basketball Grading System (CBGS). Two-way analysis of variance showed high point players to perform better compared with low point players for the majority of variables determining the quality of game performance. A lack of significant differences between two adjacent classes was explained on the basis of the methodological approach, the class-position relationship in this sample, and the performance level of women's wheelchair basketball. We conclude that the performance of elite female wheelchair basketball players is dependent on functional ability.     

Adolescent elite Kenyan runners are at risk for energy deficiency,menstrual dysfunction and disordered eating

Limited data are available on the female athlete triad (Triad) in athletes from minority groups. We explored subclinical and clinical Triad components amongst adolescent elite Kenyan athletes (n = 61) and non-athletes (n = 49). Participants completed demographic, health, sport and menstrual history questionnaires as well as a 5-day weighed dietary record and exercise log to calculate energy availability (EA). Ultrasound assessed calcaneus bone mineral density (BMD). Eating Disorder Inventory subscales and the Three-Factor Eating Questionnaire’s cognitive dietary restraint subscale measured disordered eating (DE). EA was lower in athletes than non-athletes (36.5 ± 4.5 vs. 39.5 ± 5.7 kcal ? kg FFM^?1 ? d^?1, P = 0.003). More athletes were identified with clinical low EA (17.9% vs. 2.2%, OR = 9.5, 95% CI 1.17–77, P = 0.021) and clinical menstrual dysfunction (32.7% vs. 18.3%, χ² = 7.1, P = 0.02). Subclinical (75.4% vs. 71.4%) and clinical DE (4.9% vs. 10.2%, P = 0.56) as well as BMD were similar between athletes and non-athletes. More athletes had two Triad components than non-athletes (8.9% vs. 0%, OR = 0.6, 95% CI 0.5–6.9, P = 0.05). Kenyan adolescent participants presented with one or more subclinical and/or clinical Triad component. It is essential that athletes and their entourage be educated on their energy needs including health and performance consequences of an energy deficiency.     

基于因子分析法构建世界优秀女子沙滩排球运动员运动成绩回归模型

目的：探讨世界女子沙滩排球运动员基本情况、运动技术与综合实力（因子得分）之间的关系;构建综合实力（因子得分）与运动成绩间最优模型。方法：以2012年伦敦奥运会女子沙滩排球项目所有参赛的24对（共计48名）运动员为研究对象,采用因子分析法探讨运动员基本情况、运动技术与综合实力（因子得分）之间的关系,采用回归法构建综合实力（因子得分）与运动成绩间最优模型。结果：（1）基本技术因子、主动得分因子、基本条件因子和体型因子分别占世界女子沙滩排球运动员基本情况、运动技术构成比例的49.9%,13.8%,12.7%和11.3%。（2）对三个回归模型和模型偏回归系数进行检验,发现因子得分3和因子得分4不能被引入模型。结论：（1）世界女子沙滩排球运动员基本情况、运动技术构成主要体现在基本技术因子和主动得分因子。（2）综合实力（因子得分）与运动成绩间的最优回归模型应以因子得分1和因子得分2为自变量,奥运名次为因变量来构建的多元线性回归方程。     

对优秀男子篮球运动员运动寿命的研究

优秀男子篮球运动员的运动寿命在此特指运动员竞技能力达到高水平以后 ,正常情况下持续到不能再适应其原来参加的高水平重大比赛而退役的一段时间。这段时间的长短受到多方面因素的制约和影响 ,是一个复杂的问题。本文通过对不同时期中外优秀男子篮球运动员年龄的统计发现 :他们的年龄普遍有增长的趋势 ;他们的运动寿命普遍有延长的趋势。我们应该重新认识和划分优秀男子篮球运动员的年龄阶段 ,在注重培养新秀的同时 ,也要充分发挥“老将”的作用。     

The relationship between functional potential and field performance in elite female wheelchair basketball players

The functional classification system for wheelchair basketball is based on an analysis of the players' functional resources through field-testing and game observation. Under this system, players are assigned a score of 1 to 4.5. The aim of this study was to determine if the wheelchair basketball player classification system reflects the existing differences in performance of elite female players. During the World Championship for Wheelchair Basketball in Sydney 1998, eight teams were videotaped for three 40-min games for a total of 120?min per team. Fifty-nine female players (Class I [1 and 1.5 points] n?=?12; Class II [2 and 2.5 points] n?=?20; Class III [3 and 3.5 points] n?=?13; Class IV [4 and 4.5 points] n?=?14) were retained for a detailed performance analysis by means of the Comprehensive Basketball Grading System (CBGS). Two-way analysis of variance showed high point players to perform better compared with low point players for the majority of variables determining the quality of game performance. A lack of significant differences between two adjacent classes was explained on the basis of the methodological approach, the class–position relationship in this sample, and the performance level of women's wheelchair basketball. We conclude that the performance of elite female wheelchair basketball players is dependent on functional ability.     

Effects of volleyball match-induced fatigue on knee joint position sense

Abstract

It has been suggested that a greater number of injuries during the last third of practice sessions or matches could be related to alteration of lower limb neuromuscular control due to neuromuscular fatigue. This fatigue-related effect can be mediated by changes in joint proprioception. In athletes, the use of functional fatigue protocols could have the advantage of mimicking the demands of sporting activity, thus reflecting more specifically the changes in neuromuscular control and proprioception observed in sport settings. The purpose of the present study was to assess the effect of fatigue induced by a volleyball match on knee joint position sense in elite volleyball players. Seventeen female volleyball players aged 18.9±4.2 years from the Portuguese national team volunteered for the study. Knee joint position sense was evaluated by an open kinetic chain technique and active knee positioning, and was reported using absolute, relative, and variable angular errors. Joint position sense measures were obtained before and immediately after a simulated volleyball match of five sets. To ensure that the match was sufficiently intense to induce fatigue, the perceived exertion or exercise intensity was assessed at the end of the match using Borg’ s rating of perceived exertion (RPE) scale. All participants completed the volleyball match (90min duration), reaching or exceeding 15 on the RPE scale (15.59±0.71; range 15–17), equivalent to “hard/heavy work”. After the volleyball match, a significant increase in absolute (2.11°) and relative (1.71°) angular errors was detected. Match-induced fatigue significantly exacerbated the overestimation of the test position. Moreover, the reliability and accuracy in estimating knee angles decreased from rest to the fatigued state, as shown by the increase (264%) in variable error. Our results show that fatigue induced by a volleyball match has a marked effect on knee joint position sense in elite female volleyball players. Knee joint position sense was less accurate and less consistent after the volleyball match. Fatigue induced by a simulated competitive volleyball match resulted in proprioceptive deficits, decreasing sensorimotor system acuity in female volleyball players.     

我国优秀女子三人篮球运动员比赛和训练的运动负荷特征比较

目的：通过探索我国女子三人篮球运动项目自身独特的比赛负荷特征,为我国女子三人篮球运动的训练与比赛提供理论和实践参考,指导训练和比赛,以期提升我国女子三人篮球的竞技水平。方法：使用SIMI Scout技战术分析系统和Polar Improve系统,测量和分析我国女子三人篮球队在国际比赛、队内比赛和对抗训练中的运动负荷。结果：在国际比赛中,我国优秀女子三人篮球运动员的单位时间跑动距离要显著低于同场竞技的外国选手;国内比赛中成年优秀选手与青年选手在单位时间跑动距离上没有明显差异;我国优秀女子三人篮球运动员在国际比赛和队内比赛中的单位时间跑动距离也没有明显差异。我国优秀女子三人篮球运动员在正式比赛中的最大心率和平均心率均显著性高于对抗训练,最小心率则无明显差异。在不同速度区域的跑距占比分析中,比赛和对抗训练的跑距占比均随着速度的提升而下降;在速度区1和速度区2中,正式比赛的跑距占比要显著高于对抗训练,而在速度区3和速度区4中,比赛的跑距占比则要显著低于对抗训练。结论：我国优秀三人女子篮球运动员国际大赛中的运动负荷要低于国际高水平运动员;可根据对抗训练和正式比赛的运动负荷特征,对对抗训练的运动负荷进行调整,以期达到正式比赛的预期运动负荷。     

浅析影响我国优秀篮球运动员运动寿命的因素

当今世界体坛竞争越来越激烈,优秀竞技运动员的培养一直被认为是各国发展竞技体育的重要任务之一,加之现代社会越来越追求经济效益的最大化,所以在竞技运动体育中如何延长优秀竞技运动员的运动寿命、追求最大训练效益,是当前我国体育主管部门亟待解决的问题.本文运用文献资料、数理统计等研究方法,通过对中外优秀篮球运动员的运动寿命以及参加第29界奥运会男篮前三名队伍和中国队队员的年龄情况比较分析得出结论,并指出影响我国优秀篮球运动员运动寿命的因素.     

Perceived vulnerabilities of female athletes to the development of disordered eating behaviours

Abstract

Disordered eating in athletes is an issue of concern given its prevalence and links with negative health outcomes. The purpose of this study was to examine female athletes’ perceived vulnerabilities to the development of disordered eating. Semi-structured interviews were conducted with 17 female, competitive athletes from a variety of sports who self-reported disordered eating behaviours. The results confirm previous research that sport's emphasis on the body and appearance is a factor of vulnerability. Personal qualities of perfectionism, achievement-motivation, self-absorption, competitiveness and self-control, were also described as vulnerabilities to disordered eating behaviours. The participants’ abilities to tolerate pain and to enjoy hunger pains also reportedly increased their vulnerability to disordered eating. It is suggested that the qualities valued by competitive sport may also be potential factors of vulnerability to disordered eating. The findings are discussed in terms of recommendations for future research and practice.     

Standard score assessment on physique and performance of Brazilian athletes in a six tiered competitive sports model

The use of large cross-sectional norms on Brazilian children and youths aged 7 to 18 years within a six level competition plan helps to assess development status and monitor change. Non-athletic prototypes for comparative purposes are illustrated by the use of the lowest competitive level of 18 year olds to assess differences from internationally elite players. The purpose of this study was to establish the efficacy of this practice in male and female basketball and volleyball samples. Comparisons were made on 11 anthropometric and performance variables using percent difference (% delta) and z-score values. The z-scores were highest for height, weight, and jumping ability in both sports groups. The volleyball players were the more linear in physique and the better jumpers. Related to their prototypes the female basketball players had the highest estimated VO2 max (ml kg-1 min-1), and the best values of anaerobic power measures. It is concluded that differences in physique and performance at various levels of competition compared to non-athletic prototypes may be used to infer selective and training factors.     

西安市中学生篮球运动员心理控制点类型的研究

运用文献资料法、量表测量法、专家访谈法和数理统计法,对196名西安市中学生篮球运动员进行调查和测试。结果表明:西安市中学生篮球运动员对于运动成功或运动失败在总体上具有适宜的心理控制点结构;女运动员比男运动员更具有偏向于内部控制的趋势;在成功内控的得分上,后卫比中锋、前锋更具有偏向于内部控制的趋势,在失败内控的得分上,无显著性差异;主力运动员比非主力运动员更具有偏向于内部控制的趋势。     

Differences in maturity,morphological and physical attributes between players selected to the primary and secondary teams of a Portuguese Basketball elite academy

The present study aims (i) to compare the maturational, morphological and fitness attributes of young basketball players of primary and secondary teams of an elite basketball academy, and (ii) to identify the set of morphological and fitness attributes which better discriminate the players from the two teams. A total of 116 male basketball players of an elite basketball academy were divided into primary (team A) and secondary (team B) teams in two age groups (U-14 and U-16). All the players were evaluated during two consecutive seasons and data related to players’ practice experience, maturational, morphological and fitness attributes were collected at the beginning of the competition period. The results of the study suggest that: (i) in both age categories, team A players were older, more mature, bigger in size and had greater fitness profiles than team B players; (ii) stature and abdominal resistance were identified as discriminant attributes for youth basketball player performance; (iii) aerobic capacity for U-14 and agility for U-16 were identified as specific discriminant attributes for performance in youth basketball. Coaches are recommended to avoid premature talent identification and provide players with opportunities to progress through the talent pathway, at least until U-16 age category.     

Disordered eating in male athletes: a meta-analysis

We examined the propensity for male athletes to exhibit symptoms of disordered eating. Using meta-analytic techniques, we examined overall effect size, individual effect sizes for specific sport types, standard of athletic competition and diagnostic tools from 31 studies. When all studies were considered as a homogeneous group, male athletes did not have symptoms of disordered eating that were significantly different from non-athletic controls. However, significant moderator effects emerged for sport type and measurement: (a) wrestling reported a greater incidence of disordered eating; and (b) studies that reported data from the Eating Attitudes Test yielded a significantly greater incidence of disordered eating in male athletes compared to non-athletes. Although some sports seem to present a higher risk of disordered eating compared to others, the effects are weak and heterogeneous. We make suggestions for the development of the research area, which has been severely hampered by the diagnostic tools that have been available for the study of men.     

我国优秀女子水球运动员身体成分及身体机能特征研究

目的：研究我国优秀女子水球运动员身体成分与身体机能特点,为水球运动的发展提供研究和实践参考。方法：采用BODPOD空气置换法,对自我国5支省代表队的55名优秀女子水球运动员进行体成分与身体机能测试,并按照运动等级的不同进行统计分析。结果：55名运动员的体脂百分比（％）为24．02±4．86;健将级运动员比一级运动员的体重、握力与台阶指数都明显较大,差异具显著性（p〈0．05）,其它机能指标不具显著差异;我国优秀女子水球运动员的体脂百分比我国优秀女子游泳运动员高。结论：本研究提供了一些反映女子水球运动体质要求特点的测试数据;发现女子水球运动员有较高的体脂含量,应控制身体脂肪含量;健将级运动员比一级运动员体重更大,有更强的心肺功能与上肢力量。     

我国优秀女排运动员专项力量发展水平的检查与评定

对排球运动员力量发展情况进行检查与评定。可使教练员和运动员了解力量训练工作的进展情况。有利于教练员科学地制订力量训练计划和调控训练。运用文献资料研究、问卷调查、数理统计等方法,从分析我国优秀女排运动员的专项力量特征入手。对该问题进行了探讨和研究,筛选出助跑摸高、5次连续摸高、半场米字移动、15次快速“背伸”、5次快速收腹卧推、小球掷远7项评价指标,并进行了主成分分析。以期为女排选材和训练工作提供一定参考。     

Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players

The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.     

Foreign players and competitive balance in Greek basketball and handball championships

One of the key issues of team sport championships is competitive balance. One of the dimensions of competitive balance is concerned with the differences in sporting capabilities of teams within a season. The aim of this study is to evaluate competitive balance in Greek basketball and handball championships in relation to the presence and number of foreign players. The examined periods are from 1965–1966 to 2012–2013 (n = 47) for basketball and from 1983–1984 to 2012–2013 (n = 30) for handball. Foreign players appeared in basketball starting from 1988 while in handball from 1999. For each season and sport, two global and three special indices that capture competitive balance in the multileveled championship structure were calculated. Results showed that the number of foreign players per team is dependent on the country's macroeconomic status and in its turn improves the overall competitiveness, as well as competitiveness at the relegation level. In handball foreign players appeared later and in lesser numbers than in basketball. The increase in competitiveness of the national basketball league as a result of the increase in numbers of foreign players across all teams was followed by an upsurge in the quality, performance and achievements of the top teams participating in the European competitions.