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1.
The aims of this study were to examine the use of the critical velocity test as a means of predicting 2000-m rowing ergometer performance in female collegiate rowers, and to study the relationship of selected physiological variables on performance times. Thirty-five female collegiate rowers (mean ± s: age 19.3 ± 1.3 years; height 1.70 ± 0.06 m; weight 69.5 ± 7.2 kg) volunteered to participate in the study. Rowers were divided into two categories based on rowing experience: varsity (more than 1 year collegiate experience) and novice (less than 1 year collegiate experience). All rowers performed two continuous graded maximal oxygen consumption tests (familiarization and baseline) to establish maximal oxygen uptake (VO(2max)), peak power output, and power output at ventilatory threshold. Rowers then completed a critical velocity test, consisting of four time-trials at various distances (400 m, 600 m, 800 m, and 1000 m) on two separate days, with 15 min rest between trials. Following the critical velocity test, rowers completed a 2000-m time-trial. Absolute VO(2max) was the strongest predictor of 2000-m performance (r = 0.923) in varsity rowers, with significant correlations also observed for peak power output and critical velocity (r = 0.866 and r = 0.856, respectively). In contrast, critical velocity was the strongest predictor of 2000-m performance in novice rowers (r = 0.733), explaining 54% of the variability in performance. These findings suggest the critical velocity test may be more appropriate for evaluating performance in novice rowers.  相似文献   

2.
Abstract

In this study, we evaluated the extent to which 2000-m rowing ergometer performance times predicted final rankings at the World Rowing Championships in a sample of 638 rowers of both sexes and body-mass classifications (i.e. open-category and lightweight rowers). Rowing ergometer performance times were examined using a questionnaire, and in 17 of 23 events they were positively correlated (P ≤ 0.049) with the final rankings at the Championships. The highest correlations were for the ergometer performance times achieved by rowers in lightweight men's single sculls (r = 0.78; P = 0.005), women's single sculls (r = 0.75; P = 0.002), men's single sculls (r = 0.72; P = 0.004), and lightweight men's double sculls (r = 0.72; P < 0.001). We used linear regression to establish regression equations to predict final rankings based on 2000-m rowing ergometer performance times for each event in which there was a correlation greater than r = 0.50. Although correlations in 12 events met this criterion, the large standard errors of the estimate hindered ranking predictions in all of the studied events. Regression equations could be used to determine the most probable 2000-m ergometer performance time for a rower to achieve specific rankings at the World Rowing Championships.  相似文献   

3.
ABSTRACT

Post-activation potentiation likely acutely improves power-based performance; however, few studies have demonstrated improved endurance performance. Forty collegiate female rowers performed isometric potentiating (ISO), dynamic potentiating (DYN) and control (CON) warm-up protocols on a rowing ergometer, followed by a three-minute all-out test to evaluate their total distance, peak power, mean power, critical power, anaerobic working capacity (W’) and stroke rate. Fifteen-second splits were also analysed. ISO consisted of 5 × 5-second static muscle actions with the ergometer handle rendered immovable with a nylon strap, while DYN consisted of 2 × 10-second all-out rowing bouts, separated by a 2-minute rest interval. The participants were divided into high and low experience groups by median experience level (3.75 years) for statistical analysis. Significant differences (DYN > CON; p < 0.05) were found for distance (+5.6 m), mean power (+5.9 W) and W’ (+1561.6 J) for more experienced rowers (n = 19) and no differences for less experienced rowers (n = 18). Mean power in DYN was significantly greater than CON and ISO in the 15–30, 30–45, 45–60 and 60–75 second intervals independent of experience level. These results suggest that DYN may benefit experienced female rowers and that these strategies might benefit a greater power output over shorter distances regardless of experience.  相似文献   

4.
Abstract

The aim of this study was to examine the effect of menstrual cycle phase on 2000-m rowing ergometry performance. Since high concentrations of oestrogen, indicative of the mid-luteal phase of the menstrual cycle, tend to decrease glycogen utilization and reduce blood lactate concentration, it was predicted that time taken to complete a 2000-m rowing trial would be shorter in the mid-luteal phase. Ten eumenorrhoeic, recreationally trained, female volunteers (mean age 33.0 years, s=7.1) completed 2000-m time trials on a Concept 2 rowing ergometer, in both the mid-follicular and mid-luteal phases of their menstrual cycle. In each phase, a 3-min incremental rowing protocol was used to determine a blood lactate concentration of 4 mmol · l?1 (T lac-4mM) and maximum oxygen consumption (VO2max); a five-stroke maximal test was used to establish maximal power. Order of testing was randomized for menstrual cycle phase. Variables (T lac-4mM, VO2max, maximal power) were correlated with speed in the 2000-m time trials, and the effect of menstrual cycle phase on these variables was examined. A blood lactate concentration of 4 mmol · l?1 occurred at a significantly higher mean exercise intensity (mid-luteal vs. mid-follicular: 169.1 W, s=39.1 vs. 159.0 W, s=38.3; P=0.033), heart rate (179 beats · min?1, s=9 vs. 173 beats · min?1, s=11; P=0.0047), and oxygen consumption (2.64 litres · min?1, s=0.66 vs. 2.42 litres · min?1, s=0.62; P=0.04) in the mid-luteal phase than in the mid-follicular phase. There was no significant difference (P=0.11) in 2000-m time trial speed according to menstrual cycle phase. In conclusion, although T lac-4mM differed due to menstrual cycle phase, 2000-m rowing performance was unaffected. Further research into the effects of menstrual cycle on rowing performance of a longer duration, among a more homogenous group of females, is recommended.  相似文献   

5.
ABSTRACT

Purpose: The effect of breakfast omission on evening high-intensity exercise performance has not previously been studied. Methods: In a randomised and counterbalanced cross-over design, 10 competitive rowers (2 male, 8 female; mean?±?SD: age 21?±?2 y, height 176?±?7?cm, weight 76?±?12?kg, body fat 19.7?±?6.8%) completed two trials (individualised carbohydrate-rich breakfast (BT; 831?±?67?kcal eaten before 09:00) and no-breakfast (NBT; extended overnight fast until 12:00)). Following ad libitum afternoon food intake, participants completed a 2000-m time-trial on a rowing ergometer between 16:30 and 18:00. Appetite and energy intake were measured throughout the day, whilst power output, time, heart rate, blood lactate, blood glucose and RPE were assessed during the time trial. Results: Appetite ratings were higher throughout the morning in NBT compared with BT, but there were no differences in ratings in the afternoon. Energy intake at lunch was greater NBT compared with BT (1236?±?594 vs 836?±?303?kcal, p?<?.05), which partly compensated for breakfast omission, although overall energy intake tended to be lower in NBT compared with BT (1236?±?594 vs 1589?±?225?kcal, p?=?.08). The time taken to complete the 2000-m time trial was greater in NBT compared with BT (469.2?±?43.4 vs 465.7?±?43.3?s; p?<?.05). No differences in heart rate, blood glucose and blood lactate responses were apparent, but overall RPE was higher in NBT compared with BT (17.8?±?0.9 vs 16.7?±?0.7?au, p?<?.05). Conclusion: The omission of a carbohydrate-rich breakfast impaired evening performance during a 2000-m rowing time trial. This finding has implications for optimising evening high-intensity exercise performance.  相似文献   

6.
In 19 elite schoolboy rowers, the relationships between anthropometric characteristics, metabolic parameters, strength variables and 2000-m rowing ergometer performance time were analysed to test the hypothesis that a combination of these variables would predict performance better than either individual variables or one category of variables. Anthropometric characteristics, maximal oxygen uptake (V O 2m ax ), accumulated oxygen deficit, net efficiency, leg strength and 2000-m rowing ergometer time were measured. Body mass, V O 2max and knee extension correlated with 2000-m performance time (r = -0.41, -0.43 and-0.40, respectively; P 0.05), while net efficiency and accumulated oxygen deficit did not. Multiple-regression analyses indicated that the prediction model using anthropometric variables alone best predicts performance (R = 0.82), followed by the equation comprising body mass, V O 2max and skinfolds (R = 0.80). Although the regression equations increased the predictive power from that obtained using single variables, the hypothesis that a prediction model consisting of variables from different physiological categories would predict performance better than variables from one physiological category was not supported.  相似文献   

7.
This case study reports the results of a 12-year (2005–2016) follow-up study of two Olympic champion rowers. The rowers were prospective athletes at the junior level when the study began, and we monitored their relevant physiological and performance data annually. Our findings indicated that their V?O2max gradually increased up to about 22 years of age and leveled off at a value of approximately 7 l·min?1 with minimal fluctuations thereafter. However, the variables that directly influence the V?O2max changed. There was an age-related decline in maximal heart rate of about 0.5 beats·year?1, while oxygen pulse, which serves as an indirect measure of stroke volume, correspondingly increased by about 1 ml O2·beat?1 per year, allowing the athletes to maintain exceptional V?O2max values. Maximal minute power of the studied rowers, derived each year from their ramp-wise tests, closely resembled the mean power output sustained during the 2000-m all-out tests on a rowing ergometer. A 12-year improvement of 28% and 33% occurred for the mean power output sustained over 2000 and 6000-m on a rowing ergometer, respectively. The findings contribute to the body of knowledge on athletes representing the true elites of their respective sports.  相似文献   

8.
ABSTRACT

Participant and protocol factors affect post-activation potentiation response. Performance enhancement is more consistent in highly-trained participants following multiple sets of a biomechanically similar conditioning activity. Providing optimal conditions, 6 international-level sprint cyclists executed multiple sets of short maximal conditioning contractions on a high-inertia ergometer before metered sprint performance. Three trial conditions were completed on separate days after a standardised warm-up: dynamic (DYN: 4 × 4 crank-cycles), isometric (ISO: 4 × 5-sec maximal voluntary contraction (MVC)), and control (CON: rest). Performance was measured from standing start to maximum velocity on an inertial-load ergometer at baseline (Pre), 4 (Post4), 8 (Post8) and 16 (Post16) min post-conditioning. Performance and biomechanical measures were assessed across 4 sprint segments, with magnitude-based inferences used to assess the likelihood that any affect was beneficial. Performance time only improved in DYN Post4, a 3.9% reduction during the first crank cycle (92% likely). On the ascending limb of the power-cadence relationship, peak torque and average power increased by 6.2% (94% likely) and 4.0% (87% likely), respectively. In ISOPost16, optimal cadence increased (82% likely) and average power improved over the descending limb (76% likely). DYN and ISO potentiated extremities of the torque-cadence relationship at distinct recovery times post-conditioning. This study suggests merit in including a high-inertia warm-up for sprint cycling.  相似文献   

9.
ABSTRACT

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min “all-out” race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH2O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH2O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min “all-out” test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women.

Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec  相似文献   

10.
11.
ABSTRACT

The purpose of this systematic review with meta-analysis was to examine the effects of strength training (ST) on selected components of physical fitness (e.g., lower/upper limb maximal strength, muscular endurance, jump performance, cardiorespiratory endurance) and sport-specific performance in rowers. Only studies with an active control group were included if they examined the effects of ST on at least one proxy of physical fitness and/or sport-specific performance in rowers. Weighted and averaged standardized mean differences (SMD) were calculated using random-effects models. Subgroup analyses were computed to identify effects of ST type or expertise level on sport-specific performance. Our analyses revealed significant small effects of ST on lower limb maximal strength (SMD = 0.42, p = 0.05) and on sport-specific performance (SMD = 0.32, p = 0.05). Non-significant effects were found for upper limb maximal strength, upper/lower limb muscular endurance, jump performance, and cardiorespiratory endurance. Subgroup analyses for ST type and expertise level showed non-significant differences between the respective subgroups of rowers (p ≥ 0.32). Our systematic review with meta-analysis indicated that ST is an effective means for improving lower limb maximal strength and sport-specific performance in rowers. However, ST-induced effects are neither modulated by ST type nor rowers’ expertise level.  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

Mobile power meters provide a valid means of measuring cyclists’ power output in the field. These field measurements can be performed with very good accuracy and reliability making the power meter a useful tool for monitoring and evaluating training and race demands. This review presents power meter data from a Grand Tour cyclist’s training and racing and explores the inherent complications created by its stochastic nature. Simple summary methods cannot reflect a session’s variable distribution of power output or indicate its likely metabolic stress. Binning power output data, into training zones for example, provides information on the detail but not the length of efforts within a session. An alternative approach is to track changes in cyclists’ modelled training and racing performances. Both critical power and record power profiles have been used for monitoring training-induced changes in this manner. Due to the inadequacy of current methods, the review highlights the need for new methods to be established which quantify the effects of training loads and models their implications for performance.  相似文献   

14.
Abstract

To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of the players at the end of the first season was 14.2 years (s = 1.1). Repeated-measures analyses of covariance, with standard of performance and measurement occasion as factors and age as a covariate, showed that the elite players fared better than the sub-elite players on technical and tactical variables. Female elite youth players also scored better on interval endurance capacity, motivation, and confidence. Future elite players appear to have excellent tactical skills by the age of 14. They also have good specific technical skills and develop these together with interval endurance capacity better than sub-elite youth players in the subsequent 2 years. To verify our conclusions, we will be tracking these players into adulthood.  相似文献   

15.
Objectives: To investigate the effects that high-velocity, low-load (HVLL) and low-velocity, high-load (LVHL) resistance exercise, performed once or twice-weekly, have on indices of functional performance (primary outcome), maximal strength, and body composition (secondary outcomes) in older adults.

Methods: In a randomised, controlled, multi-armed, parallel design, 54 moderately-highly active, but resistance exercise naïve older adults (aged 60–79 years), attended baseline and post-10-week intervention assessment sessions. Physical and functional assessments were completed, and predicted one-repetition maximums (1-RM) were obtained for eight exercises. Participants were then randomised into one of five conditions: HVLL once-weekly (HVLL1: n?=?11) or twice-weekly (HVLL2: n?=?11), LVHL once-weekly (LVHL1: n?=?10) or twice-weekly (LVHL2: n?=?11), no-exercise control condition (CON: n?=?11). The HVLL conditions completed 3 sets of 14 repetitions at 40% 1-RM and the LVHL conditions, 3 sets of 7 repetitions at 80% 1-RM. In total, 50 participants completed all testing and were included in analyses.

Results: Only LVHL2 improved 30-sec chair stand performance (p?=?.035; g?=?0.89), arm curls (p?=?.011; g?=?1.65) and grip-strength (p?=?.015; g?=?0.34) compared to CON. LVHL2 improved maximal strength compared to CON for 7/8 exercises (p?p?Conclusion: Possibly due to the lower intensity nature of the HVLL conditions, LVHL, twice-weekly was most beneficial for improving functional performance and strength in moderately-highly active older adults. Therefore, we recommend that exercise professionals ensure resistance exercise sessions have sufficient intensity of effort and volume, in order to maximise functional performance and strength gains in older adults.  相似文献   

16.
ABSTRACT

Considering the scarce empirical evidence regarding talent predictors in female youth soccer, the present study aimed to investigate the long-term prognostic validity of elite female soccer players’ adolescent motor performance for future success in adulthood. Additionally, the three-year development of highly talented girls’ motor performance and the predictive value of this motor development for reaching a professional adult performance level (APL) was analysed.

Overall, N = 737 female players participated in nationwide motor diagnostics (sprinting, agility, dribbling, ball control, shooting) within the German Soccer Association’s talent identification and development programme at least twice between the age groups Under-12 (U12) and U15. Based on their APL at least four years later, participants were assigned to a professional (first German division, 6.2%) or non-professional group (lower divisions, 93.8%).

Multilevel regression analyses revealed a general prognostic relevance for the investigated parameters with respect to players’ APL. In addition, there was a non-linear improvement in participants’ motor performance across all variables from U12 to U15. However, non-significant interactions between APL and these improvements indicate motor performance development itself cannot adequately predict players’ future success in adulthood. Findings provide insightful information that can help coaches foster optimal support for young female soccer players’ development.  相似文献   

17.
The aim of this work was to identify, synthesize and evaluate the results of randomized controlled trials examining the effects of resistance training on performance indicators in previously trained endurance runners. A database search was carried out in PubMed, Science Direct, OvidSPMedLine, Wiley, Web of Science, ProQuest and Google Scholar. In accordance with the PRISMA checklist, 18 published articles dated prior to May 2016 involving 321 endurance runners were reviewed using the PEDro scale. Resistance training led to general improvements in muscular strength, running economy, muscle power factors, and direct performance in distances between 1,500 and 10,000 m. Such improvements were not accompanied by a significant increase in body mass or signs of overtraining. However, improvements did not occur in all cases, suggesting that they might depend on the specific characteristics of the resistance training applied. Although current evidence supports the effectiveness of resistance training to improve performance in already trained endurance runners, the methodological inconsistencies identified suggest that the results should be interpreted with caution. Future studies ought to investigate the benefits of resistance training in endurance runners while considering the existence of possible differentiated effects based on the specific characteristics of the resistance training carried out.  相似文献   

18.
19.
以Web of ScienceTM(以下简称WoS)核心合集数据库收录的近20年体育符号相关的354篇英文文献为数据来源,对其进行文献计量和内容分析。发现:体育符号研究年度发文量在整体上呈上升趋势,发文期刊集中在体育史及体育社会研究领域;近20年的体育符号研究可划分为基础研究、快速发展、深入发展3个阶段;研究者主要关注体育符号在其意义生成过程中与经济、政治、文化、教育等符号系统及与社会成员之间的互动,并采取了历时性、内部性、整体性视角进行研究;研究材料来源多样化,且研究方法的运用呈现综合化、创新化特征。  相似文献   

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