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1.
Abstract

This study investigated the effects of upper-body repeated-sprint training in hypoxia vs. in normoxia on world-level male rugby union players’ repeated-sprint ability (RSA) during an international competition period. Thirty-six players belonging to an international rugby union male national team performed over a 2-week period four sessions of double poling repeated-sprints (consisting of 3 × eight 10-s sprints with 20-s passive recovery) either in normobaric hypoxia (RSH, simulated altitude 3000 m, n?=?18) or in normoxia (RSN, 300 m; n?=?18). At pre- and post-training intervention, RSA was evaluated using a double-poling repeated-sprint test (6 × 10-s maximal sprint with 20-s passive recovery) performed in normoxia. Significant interaction effects (P?<?0.05) between condition and time were found for RSA-related parameters. Compared to Pre-, peak power significantly improved at post- in RSH (423?±?52 vs. 465?±?69 W, P?=?0.002, η²=0.12) but not in RSN (395?±?65 vs. 397?±?57 W). Averaged mean power was also significantly enhanced from pre- to post-intervention in RSH (351?±?41 vs. 388?±?53 W, P?<?0.001, η²=0.15), while it remained unchanged in RSN (327?±?49 vs. 327?±?43 W). No significant change in sprint decrement (P?=?0.151, η²?=?0.02) was observed in RSH (?17?±?2% vs. ?16?±?3%) nor RSN (?17?±?2% vs. ?18?±?4%). This study showed that only four upper-body RSH sessions were beneficial in enhancing repeated power production in international rugby union players. Although the improvement from RSA to game behaviour remains unclear, this finding appears of practical relevance since only a short preparation window is available prior to international games.  相似文献   

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3.
The study aimed to evaluate the mediating effect of biological maturation on anthropometrical measurements, performance indicators and subsequent selection in a group of academy rugby union players. Fifty-one male players 14–17 years of age were assessed for height, weight and BMI, and percentage of predicted mature status attained at the time of observation was used as an indicator of maturity status. Following this, initial sprint velocity (ISV), Wattbike peak power output (PPO) and initial sprint momentum (ISM) were assessed. A bias towards on-time (n?=?44) and early (n?=?7) maturers was evident in the total sample and magnified with age cohort. Relative to UK reference values, weight and height were above the 90th and 75th centiles, respectively. Significant (p?≤?.01) correlations were observed between maturity status and BMI (r?=?.48), weight (r?=?.63) and height (r?=?.48). Regression analysis (controlling for age) revealed that maturity status and height explained 68% of ISM variance; however, including BMI in the model attenuated the influence of maturity status below statistical significance (p?=?.72). Height and BMI explained 51% of PPO variance, while no initial significant predictors were identified for ISV. The sample consisted of players who were on-time and early in maturation with no late maturers represented. This was attributable, in part, to the mediating effect of maturation on body size, which, in turn, predicted performance variables.  相似文献   

4.
ABSTRACT

This study investigated the role of reactive and eccentric strength in stiffness regulation during maximum velocity sprinting (Vmax) in team sport athletes compared with highly trained sprinters. Thirteen team sport athletes and eleven highly trained sprinters were recruited. Vmax was measured using radar, and stiffness regulation was inferred from modelled vertical and leg spring stiffness. Reactive strength (RSI) was determined from a 0.50 m drop jump, and an eccentric back squat was used to assess maximum isoinertial eccentric force. Trained sprinters attained a higher Vmax than team sport athletes, partly due to a briefer contact time and higher vertical stiffness. Trained sprinters exhibited a moderately higher RSI via the attainment of a briefer and more forceful ground contact phase, while RSI also demonstrated large to very large associations with vertical stiffness and Vmax, respectively. Isoinertial eccentric force was largely correlated with Vmax, but only moderately correlated with vertical stiffness. Reactive and eccentric strength contribute to the ability to regulate leg spring stiffness at Vmax, and subsequently, the attainment of faster sprinting speeds in highly trained sprinters versus team sport athletes. However, stiffness regulation appears to be a task-specific neuromuscular skill, reinforcing the importance of specificity in the development of sprint performance.  相似文献   

5.
Purpose: The goal of this study was to determine the effects of repeated-sprint training in hypoxia induced by voluntary hypoventilation at low lung volume (VHL) on running repeated-sprint ability (RSA) in team-sport players.

Methods: Twenty-one highly trained rugby players performed, over a 4-week period, seven sessions of repeated 40-m sprints either with VHL (RSH-VHL, n?=?11) or with normal breathing (RSN, n?=?10). Before (Pre-) and after training (Post-), performance was assessed with an RSA test (40-m all-out sprints with a departure every 30?s) until task failure (85% of the reference velocity assessed in an isolated sprint).

Results: The number of sprints completed during the RSA test was significantly increased after the training period in RSH-VHL (9.1?±?2.8 vs. 14.9?±?5.3; +64%; p?p?=?.74). Maximal velocity was not different between Pre- and Post- in both groups whereas the mean velocity decreased in RSN and remained unchanged in RSH-VHL. The mean SpO2 recorded over an entire training session was lower in RSH-VHL than in RSN (90.1?±?1.4 vs. 95.5?±?0.5%, p?Conclusion: RSH-VHL appears to be an effective strategy to produce a hypoxic stress and to improve running RSA in team-sport players.  相似文献   

6.
We compared the efficacy of three physical conditioning programmes provided over a 12 week period (24?h in total) on selected anthropometric and physical fitness parameters in female soccer players. Two of the groups received physical conditioning training in accordance with speed, agility and quickness (SAQ); one group used specialized resistance and speed development SAQ equipment (equipment group; n?=?12), while the other group used traditional soccer coaching equipment (non-equipment group; n?=?12). A third group received their regular fitness sessions (active control group; n?=?12). All three interventions decreased (P?<0.001) the participants' body mass index (?3.7%) and fat percentage (?1.7%), and increased their flexibility (+14.7%) and maximal aerobic capacity ([Vdot]O2max) (+18.4%). The participants in the equipment and non-equipment conditioning groups showed significantly (P?<0.005) greater benefits from their training programme than those in the active control group by performing significantly better on the sprint to fatigue (?11.6% for both the equipment and non-equipment groups versus ?6.2% for the active control group), 25?m sprint (?4.4% vs ?0.7%), left (?4.5% vs ?1.0%) and right (?4.0% vs ?1.4%) side agility, and vertical (+18.5% vs +4.8%) and horizontal (+7.7% vs +1.6%) power tests. Some of these differences in improvements in physical fitness between the equipment and non-equipment conditioning groups on the one hand and the active control group on the other hand were probably due to the specificity of the training programmes. It was concluded that SAQ training principles appear to be effective in the physical conditioning of female soccer players. Moreover, these principles can be implemented during whole team training sessions without the need for specialized SAQ equipment. Finally, more research is required to establish the relationship between physical fitness and soccer performance as well as the principles underlying the improvements seen through the implementation of SAQ training programmes.  相似文献   

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9.
Abstract

It is a common requirement in tournament scenarios for athletes to compete multiple times in a relatively short time period, with insufficient recovery time not allowing full restoration of physical performance. This study aimed to develop a greater understanding of the physiological stress experienced by athletes in a tournament scenario, and how a commonly used recovery strategy, cold water immersion (CWI), might influence these markers. Twenty-one trained male games players (age 19?±?2; body mass 78.0?±?8.8?kg) were randomised into a CWI group (n?=?11) or a control group (n?=?10). To simulate a tournament, participants completed the Loughborough Intermittent Shuttle Test (LIST) on three occasions in five days. Recovery was assessed at specific time points using markers of sprint performance, muscle function, muscle soreness and biochemical markers of damage (creatine kinase, CK), inflammation (IL-6 and C-Reactive Protein) and oxidative stress (lipid hydroperoxides and activity of 6 lipid-soluble antioxidants). The simulated tournament was associated with perturbations in some, but not all, markers of physiological stress and recovery. Cold water immersion was associated with improved recovery of sprint speed 24?h after the final LIST (ES?=?0.83?±?0.59; p?=?.034) and attenuated the efflux of CK pre- and post-LIST 3 (p?<?.01). The tournament scenario resulted in an escalation of physiological stress that, in the main, cold water immersion was ineffective at managing. These data suggest that CWI is not harmful, and provides limited benefits in attenuating the deleterious effects experienced during tournament scenarios.  相似文献   

10.
Abstract

This study investigated the relative importance of physiological, anthropometric, and skill qualities to team selection in professional rugby league. Eighty-six high performance rugby league players underwent measurements of anthropometric (height, body mass, sum of seven skinfolds), physiological (speed, change of direction speed, lower body muscular power, repeated-sprint ability, prolonged high-intensity intermittent running ability, and maximal aerobic power), technical skill (tackling proficiency, draw and pass proficiency), and perceptual skill (reactive agility, pattern recall, pattern prediction) qualities. A linear discriminant analysis was also conducted comparing those players successful in gaining selection into the professional National Rugby League team with those not selected to determine which, if any, of these qualities could predict selection. Players selected to play in the first National Rugby League game of the season were older, more experienced, leaner, had faster 10m and 40m sprint times, and superior vertical jump performances, maximal aerobic power, tackling proficiency and dual-task draw and pass ability than non-selected players. Skinfold thickness and dual-task draw and pass proficiency were the only variables that contributed significantly (P < 0.05) to the discriminant analysis of selected and non-selected players. These findings suggest that selected physiological, anthropometric, and skill qualities may influence team selection in professional rugby league.  相似文献   

11.
The aim of this study was to identify anthropometric and biomotor variables that discriminated among groups of elite adolescent female athletes aged 14.3 ± 1.3 years (mean ± s) from four different sports (tennis, n = 15; swimming, n = 23; figure skating, n = 46; volleyball, n = 16). The anthropometric variables included body mass, height, bi-epicondylar breadth of the distal extremity of the humerus and femur, maximal girth of the calf and biceps and the sum of five adipose skinfolds. The biomotor variables were maximal aerobic power, muscular endurance and flexibility of the trunk. Discriminant analysis revealed three significant functions (P ? 0.05). The first discriminant function primarily represented differences between figure skaters and all other groups of athletes. The other two underlined anthropometric and biomotor differences between swimmers and volleyball players and between tennis players and swimmers, respectively. After validation, the analysis showed that 88% of the athletes were correctly classified in their respective sports. Our model confirms that elite adolescent female athletes show physical and biomotor differences that clearly distinguish them according to their particular sport.  相似文献   

12.
ABSTRACT

This study aimed to evaluate whether an individualised sprint-training program was more effective in improving sprint performance in elite team-sport players compared to a generalised sprint-training program. Seventeen elite female handball players (23 ± 3 y, 177 ± 7 cm, 73 ± 6 kg) performed two weekly sprint training sessions over eight weeks in addition to their regular handball practice. An individualised training group (ITG, n = 9) performed a targeted sprint-training program based on their horizontal force-velocity profile from the pre-training test. Within ITG, players displaying the lowest, highest and mid-level force-velocity slope values relative to body mass were assigned to a resisted, an assisted or a mixed sprint-training program (resisted sprinting in the first half and assisted sprinting in the second half of the intervention period), respectively. A control group (CG, n = 8) performed a generalised sprint-training program. Both groups improved 30-m sprint performance by ~1% (small effect) and maximal velocity sprinting by ~2% (moderate effect). Trivial or small effect magnitudes were observed for mechanical outputs related to horizontal force- or power production. All between-group differences were trivial. In conclusion, individualised sprint-training was no more effective in improving sprint performance than a generalised sprint-training program.  相似文献   

13.
Abstract

The present study investigated the role of chronic sport participation in the modulation of vigilance and inhibitory control. We also aimed to disentangle the relative contribution of different types of sport expertise and sport-related fitness to the exercise-cognition relationship. Three groups of young adults differing in their chronic sport expertise (externally-paced sports, n?=?22, self-paced sports, n?=?22, non-athletes, n?=?22) took part in the study. Participants completed a cardiovascular fitness test, a hand-eye coordination test and two different types of vigilance tasks: (1) Psychomotor Vigilance Task (PVT) and (2) Oddball Task, which were designed to gain insight into the cognitive processes involved in sustaining attention over time and allocating selective attention by exerting inhibitory control, respectively. No differences were found in PVT performance between the two athlete groups and between self-paced sports athletes and non-athletes, whereas athletes from externally-paced sports outperformed non-athletes. Crucially, athletes from externally-paced sports also differed from those of self-paced sports and non-athletes in the Oddball task, showing less omission and commission errors. The sport expertise effect was independent of participant’s cardiovascular fitness while hand-eye coordination modulated vigilance and inhibitory control performance. Our findings add novel empirical evidence to the role of expertise in cognitively demanding sports as an important factor in the relationship between exercise and cognition.  相似文献   

14.
Abstract

The aims of this study were to identify whether relative shape and size characteristics of world-class sprinters have changed over time, and whether any anthropometric parameters characterize the most successful world-class sprinters. The results suggest that body mass index, reflecting greater muscle mass rather than greater adiposity, is an important factor associated with success in both male and female world-class sprinters over time. However, in female athletes the reciprocal ponderal index (RPI) has emerged as a more important indicator of success over several decades, with taller, more linear sprinters achieving greater success, as measured by sprint speed. In male sprinters it is only in the most recent decade that RPI has emerged as an important predictor of success. We speculate that the prominence of the RPI and an ectomophic somatotype being typical of the most successful world-class sprinters might be explained, in part, by the influence of stride length on sprint speed. In conclusion, these results suggest that coaches, selectors, and sports scientists should consider body shape when selecting potential athletes for sprint events, encouraging more linear athletes with a high RPI.  相似文献   

15.
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.  相似文献   

16.
There is limited research studying fluid and electrolyte balance in rugby union players, and a paucity of information regarding the test–retest reliability. This study describes the fluid balance of elite rugby union players across multiple squads and the reliability of fluid balance measures between two equivalent training sessions. Sixty-one elite rugby players completed a single fluid balance testing session during a game simulation training session. A subsample of 21 players completed a second fluid balance testing session during an equivalent training session. Players were weighed in minimal clothing before and after each training session. Each player was provided with their own drinks which were weighed before and after each training session. More players gained body weight (9 (14.8%)) during training than lost greater than 2% of their initial body mass (1 (1.6%)). Pre-training body mass and rate of fluid loss were significantly associated (r?=?0.318, p?=?.013). There was a significant correlation between rate of fluid loss in sessions 1 (1.74?±?0.32?L?h?1) and 2 (1.10?±?0.31?L.?h?1), (r?=?0.470, p?=?.032). This could be useful for nutritionists working with rugby squads to identify players with high sweat losses.  相似文献   

17.
We investigated age-related differences in the relationships among acceleration, maximum running speed, and repeated-sprint performance in 61 highly trained young male soccer players (Under 14, n = 14; Under 16, n = 22; Under 18, n = 25). We also examined the possible influence of anthropometry (stature, body mass, fat-free mass) and biological maturation (age at peak height velocity) on performance in those three sprint-running qualities. Players were tested for 10-m sprint (acceleration), flying 20-m sprint (maximum running speed), and 10 × 30-m sprint (repeated-sprint performance) times. Correlations between acceleration, maximum running speed, and repeated-sprint performance were positive and large to almost perfect (r = 0.55-0.96), irrespective of age group. There were age-based differences both in absolute performance in the three sprint-running qualities (Under 18 > Under 16 > Under 14; P < 0.001) and when body mass and fat-free mass were statistically controlled (P < 0.05). In contrast, all between-group differences disappeared after adjustment for age at peak height velocity (P > 0.05). The large correlations among acceleration, maximum running speed, and repeated-sprint performance in all age groups, as well as the disappearance of between-group differences when adjusted for estimated biological maturity, suggest that these physical qualities in young highly trained soccer players might be considered as a general quality, which is likely to be related to qualitative adaptations that accompany maturation.  相似文献   

18.
Abstract

The purpose of this study was twofold: (a) to examine the stressors experienced by injured athletes during three phases of their recovery from sport injury, and (b) to explore the differences in the stressors experienced by team as compared to individual-sport athletes. Participants comprised previously injured high-level rugby union players (n = 5) and golfers (n = 5). Semi-structured interviews were used to explore the stressors participants experienced during three phases of injury (onset, rehabilitation and return to competitive sport). Within- and cross-case analyses showed that athletes experienced sport, medical/physical, social and financial stressors. There were a number of differences in the stressors experienced across the three phases and between team and individual-sport athletes. Findings have important implications for the design and implementation of interventions aimed at managing the potentially stressful sport injury experience and facilitating injured athletes' return to competitive sport.  相似文献   

19.
Purpose: In team sports, players have to manage personal interests and group goals, emphasizing intricacies between personal and social identities. The focus of this article was to examine the effect of identity mechanisms on appraisal processes, based on the following research question: Does the level of self-abstraction (low [personal identity] versus high [social identity]) lead to group-based emotions and influence performances? Method: An experimental design was used in which the level of self-abstraction was manipulated through the induction of a self- versus a team-oriented goal. Thirty elite male rugby players (Mage = 19.06, SD = 0.78, randomly split) participated in a match reproducing conditions similar to those of official games. Individual and perceived team-level emotions and performance were measured 17 times during the match. Results: Linear Mixed Effects models showed that a high level of self-abstraction: (a) led to more positive and less negative individual (variances explained: 52% and 46%) and perceived team-referent (variances explained: 57% and 40%) emotions; (b) reduced the correlation of team-referent emotions with individual ones; and (c) positively influenced team and individual performances (variances explained: 50% and 19%). Moreover, after controlling for potential effects of the level of self-abstraction, only positive team-referent emotions influenced performance. Conclusions: This study is the first to experimentally manipulate athletes’ social identity to examine group-based emotions in sport. Challenging the usual intrapersonal approaches, these findings suggested that social identity and its association with team-referent emotions could be one of the key dimensions of emotion-performance relationships in team sports.  相似文献   

20.
橄榄球运动具有团体性项目中最为激烈的对抗性,这导致橄榄球运动员出现运动损伤的风险是显著的,因此如何针对橄榄球运动损伤进行有效预防成为教练员和运动员们所关注的内容。该研究主要基于英语文献,对橄榄球项目的运动损伤特征、影响因素及监控策略进行了梳理与分析,研究表明(1)橄榄球运动员的损伤类型、部位和严重程度具有明显的橄榄球专项特征,依据橄榄球运动员主要损伤类型、部位及严重程度采取针对性的预防措施能够降低球队的伤病风险;(2)橄榄球运动员运动损伤的影响因素主要包括伤病史、比赛与训练负荷、竞技水平、年龄与性别、接触动作、球员位置以及疲劳,依据运动损伤影响因素对训练和比赛过程进行合理控制能够减少运动损伤对球队整体竞技能力的影响;(3)橄榄球运动员的损伤监控策略主要包括运动损伤预筛查、建立运动损伤监测系统以及进行多学科合作参与,通过对橄榄球运动损伤监控策略的应用和探索可以从根源上提高橄榄球队的运动损伤监控效果。  相似文献   

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