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1.
This study aimed to quantify the intra-individual reliability of a number of physiological variables in a group of national and international young distance runners. Sixteen (8 male, 8 female) participants (16.7?±?1.4 years) performed a submaximal incremental running assessment followed by a maximal running test, on two occasions separated by no more than seven days. Maximal oxygen uptake (V?O2max), speed at V?O2max (km?h?1), running economy and speed and heart rate (HR) at fixed blood lactate concentrations were determined. V?O2max and running economy were scaled for differences in body mass using a power exponent derived from a larger cohort of young runners (n?=?42). Running economy was expressed as oxygen cost and energy cost at the speed associated with lactate turnpoint (LTP) and the two speeds prior to LTP. Results of analysis of variance revealed an absence of systematic bias between trials. Reliability indices showed a high level of reproducibility across all parameters (typical error [TE] ≤2%; intra-class correlation coefficient >0.8; effect size <0.6). Expressing running economy as energy cost appears to provide superior reliability than using oxygen cost (TE ~1.5% vs. ~2%). Blood lactate and HR were liable to daily fluctuations of 0.14–0.22?mmol?L?1 and 4–5?beats?min?1 respectively. The minimum detectable change values (95% confidence) for each parameter are also reported. Exercise physiologists can be confident that measurement of important physiological determinants of distance running performance are highly reproducible in elite junior runners.  相似文献   

2.
Abstract

The main aim of this study was to determine the test–retest reliability of existing tests of health-related fitness. Participants (mean age 14.8 years, s = 0.4) were 42 boys and 26 girls who completed the study assessments on two occasions separated by one week. The following tests were conducted: bioelectrical impedance analysis (BIA) to calculate percent body fat, leg dynamometer, 90° push-up, 7-stage sit-up, and wall squat tests. Intra-class correlation (ICC), paired samples t-tests, and typical error expressed as a coefficient of variation were calculated. The mean percent body fat intra-class correlation coefficient was similar for boys (ICC = 0.95) and girls (ICC = 0.93), but the mean coefficient of variation was considerably higher for boys than girls (22.2% vs. 12.2%). The boys' coefficients of variation for the tests of muscular fitness ranged from 9.0% for the leg dynamometer test to 26.5% for the timed wall squat test. The girls' coefficients of variation ranged from 17.1% for the sit-up test to 21.4% for the push-up test. Although the BIA machine produced reliable estimates of percent body fat, the tests of muscular fitness resulted in high systematic error, suggesting that these measures may require an extensive familiarization phase before the results can be considered reliable.  相似文献   

3.
This study aimed to evaluate the test–retest reliability of a new device for assessing ankle joint kinesthesia. This device could measure the passive motion threshold of four ankle joint movements, namely plantarflexion, dorsiflexion, inversion and eversion. A total of 21 healthy adults, including 13 males and 8 females, participated in the study. Each participant completed two sessions on two separate days with 1-week interval. The sessions were administered by the same experimenter in the same laboratory. At least 12 trials (three successful trials in each of the four directions) were performed in each session. The mean values in each direction were calculated and analysed. The ICC values of test–retest reliability ranged from 0.737 (dorsiflexion) to 0.935 (eversion), whereas the SEM values ranged from 0.21° (plantarflexion) to 0.52° (inversion). The Bland–Altman plots showed that the reliability of plantarflexion–dorsiflexion was better than that of inversion–eversion. The results evaluated the reliability of the new device as fair to excellent. The new device for assessing kinesthesia could be used to examine the ankle joint kinesthesia.  相似文献   

4.
β-alanine is a common ingredient in supplements consumed by athletes. Indeed, athletes may believe that the β-alanine induced paresthesia, experienced shortly after ingestion, is associated with its ergogenic effect despite no scientific mechanism supporting this notion. The present study examined changes in cycling performance under conditions of β-alanine induced paresthesia. Eight competitive cyclists (VO2max = 61.8 ± 4.2 mL·kg·min?1) performed three practices, one baseline and four experimental trials. The experimental trials comprised a 1-km cycling time trial under four conditions with varying information (i.e., athlete informed β-alanine or placebo) and supplement content (athlete received β-alanine or placebo) delivered to the cyclist: informed β-alanine/received β-alanine, informed placebo/received β-alanine, informed β-alanine/received placebo and informed placebo/received placebo. Questionnaires were undertaken exploring the cyclists’ experience of the effects of the experimental conditions. A possibly likely increase in mean power was associated with conditions in which β-alanine was administered (±95% CL: 2.2% ± 4.0%), but these results were inconclusive for performance enhancement (p = 0.32, effect size = 0.18, smallest worthwhile change = 56% beneficial). A possibly harmful effect was observed when cyclists were correctly informed that they had ingested a placebo (–1.0% ± 1.9%). Questionnaire data suggested that β-alanine ingestion resulted in evident sensory side effects and six cyclists reported placebo effects. Acute ingestion of β-alanine is not associated with improved 1-km TT performance in competitive cyclists. These findings are in contrast to the athlete’s “belief” as cyclists reported improved energy and the ability to sustain a higher power output under conditions of β-alanine induced paresthesia.  相似文献   

5.
In-shoe plantar pressure systems are commonly used in clinical and research settings to assess foot function during functional tasks. Recently, Tekscan® has updated their F-Scan® in-shoe plantar pressure system; however, this system’s test–retest reliability has not been established. Therefore, the purpose of this study was to determine the test–retest reliability of the F-Scan® 7 system in recreationally active individuals during treadmill walking. Seventeen healthy adults completed 2 sessions of treadmill walking. For each session, participants were fitted for shoes and pressure insoles and walked on a treadmill at a self-selected pace for 30 s. Following the sessions, the test–retest reliability peak pressure, pressure time integral, average pressure and pressure contact area over 4 regions of the foot (heel, mid-foot, forefoot and toes) was assessed by calculating intraclass coefficients (ICC 2,k) and coefficient of variation percentage (CoV%). Pressure contact area consistently had the highest ICCs and lowest CoV% (ICCs: 0.91–0.98; CoV%: 2.7–7.8%). Whereas, the forefoot and toe regions had the highest ICCs for all 4 measures (ICCs: 0.83–0.98; CoV%: 3.1–13.4%). During treadmill walking in healthy recreationally active individuals, the reliability of the new Tekscan F-Scan® ranged from poor to high and was dependent on the measure and region of the foot.  相似文献   

6.
It has previously been shown that measurement of the critical speed is a non-invasive method of estimating the blood lactate response during exercise. However, its validity in children has yet to be demonstrated. The aims of this study were: (1) to verify if the critical speed determined in accordance with the protocol of Wakayoshi et al. is a non-invasive means of estimating the swimming speed equivalent to a blood lactate concentration of 4 mmol·l-1 in children aged 10-12 years; and (2) to establish whether standard of performance has an effect on its determination. Sixteen swimmers were divided into two groups: beginners and trained. They initially completed a protocol for determination of speed equivalent to a blood lactate concentration of 4 mmol·l-1. Later, during training sessions, maximum efforts were swum over distances of 50, 100 and 200 m for the calculation of the critical speed. The speeds equivalent to a blood lactate concentration of 4 mmol·l-1 (beginners = 0.82±0.09 m·s-1 , trained = 1.19±0.11 m·s-1; mean±s) were significantly faster than the critical speeds (beginners = 0.78±0.25·s-1 , trained = 1.08±0.04 m·s-1) in both groups. There was a high correlation between speed at a blood lactate concentration of 4 mmol·l-1 and the critical speed for the beginners (r = 0.96, P ? 0.001), but not for the trained group (r = 0.60, P > 0.05). The blood lactate concentration corresponding to the critical speed was 2.7±1.1 and 3.1±0.4 mmol·l-1 for the beginners and trained group respectively. The percent difference between speed at a blood lactate concentration of 4 mmol·l-1 and the critical speed was not significantly different between the two groups. At all distances studied, swimming performance was significantly faster in the trained group. Our results suggest that the critical speed underestimates swimming intensity corresponding to a blood lactate concentration of 4 mmol·l-1 in children aged 10-12 years and that standard of performance does not affect the determination of the critical speed.  相似文献   

7.
Current methods of assessing coordination in Paralympic classification are non-instrumented and are based on ordinal scales of measurement and therefore impede the development of evidence-based methods of classification. This paper describes an instrumented battery of tests that measure impaired coordination in a way that will permit evidence-based classification. Test–retest reliability and normative values for each of the tests are reported. Twenty participants visited the laboratory on two occasions, each time completing 11 tests: three running-specific, lower-limb reciprocal tapping tests (yielding five outcome measures); four throwing-specific, upper-limb discrete tapping tests (yielding four outcome measures); and four wheelchair-specific, upper-limb reciprocal tapping tests yielding seven outcome measures. Reliability was evaluated using Intra-class Correlation Coefficients (ICCs), Standard Error of Measurement, Limits of Agreement and Paired t-tests. ICCs for fourteen of the 16 outcome measures were excellent (ICC ≥ 0.80), although systematic bias was evident in two of these—a unilateral, running-specific lower-limb tests on the non-dominant side, and a unilateral wheelchair-specific upper limb test on the dominant side. ICCs for two tests—a bilateral wheelchair-specific upper limb test (0.74), and a unilateral wheelchair-specific upper limb test on the non-dominant side (0.54)—were good and fair respectively. Results indicate that 12 of the measures evaluated have measurement properties that will facilitate the development of evidence-based methods of Paralympic classification in athletics. Positional adjustment and increased familiarization may improve reliability in the other four. Studies evaluating reliability of this test battery in people with coordination impairments are warranted.  相似文献   

8.
In The Netherlands, the 4-Skills Scan is an instrument for physical education teachers to assess gross motor skills of elementary school children. Little is known about its reliability. Therefore, in this study the test–retest and inter-rater reliability was determined. Respectively, 624 and 557 Dutch 6- to 12-year-old children were analyzed for test re-test and inter-rater reliability. All tests took place within the school setting. The outcome measure was age-expected motor performance (in years). Results showed a small practice effect of .24 years for re-test sessions and assessment of motor skills was possible with acceptable precision (standard error of measurement = .67 years). Overall, intraclass correlation coefficient (ICC) was .93 (95% confidence interval: .92–.95) for test–retest reliability and .97 for inter-rater reliability. For the repeated measures, the smallest detectable change (SDC) was 1.84 and limits of agreement were –1.60 and 2.08 years. It can be concluded that the 4-Skills Scan is a reliable instrument to assess gross motor skills in elementary school children.  相似文献   

9.
The aim of this study was to develop and describe a wheelchair mobility performance test in wheelchair basketball and to assess its construct validity and reliability. To mimic mobility performance of wheelchair basketball matches in a standardised manner, a test was designed based on observation of wheelchair basketball matches and expert judgement.

Forty-six players performed the test to determine its validity and 23 players performed the test twice for reliability. Independent-samples t-tests were used to assess whether the times needed to complete the test were different for classifications, playing standards and sex. Intraclass correlation coefficients (ICC) were calculated to quantify reliability of performance times.

Males performed better than females (< 0.001, effect size [ES] = ?1.26) and international men performed better than national men (< 0.001, ES = ?1.62). Performance time of low (≤2.5) and high (≥3.0) classification players was borderline not significant with a moderate ES (= 0.06, ES = 0.58). The reliability was excellent for overall performance time (ICC = 0.95).

These results show that the test can be used as a standardised mobility performance test to validly and reliably assess the capacity in mobility performance of elite wheelchair basketball athletes. Furthermore, the described methodology of development is recommended for use in other sports to develop sport-specific tests.  相似文献   

10.
The purpose of this study was to quantify the inter-session reliability of force–velocity–power profiling and estimated maximal strength in youth. Thirty-six males (11–15 years old) performed a ballistic supine leg press test at five randomized loads (80%, 100%, 120%, 140%, and 160% body mass) on three separate occasions. Peak and mean force, power, velocity, and peak displacement were collected with a linear position transducer attached to the weight stack. Mean values at each load were used to calculate different regression lines and estimate maximal strength, force, velocity, and power. All variables were found reliable (change in the mean [CIM] = ? 1 to 14%; coefficient of variation [CV] = 3–18%; intraclass correlation coefficient [ICC] = 0.74–0.99), but were likely to benefit from a familiarization, apart from the unreliable maximal force/velocity ratio (CIM = 0–3%; CV = 23–25%; ICC = 0.35–0.54) and load at maximal power (CIM = ? 1 to 2%; CV = 10–13%; ICC = 0.26–0.61). Isoinertial force–velocity–power profiling and maximal strength in youth can be assessed after a familiarization session. Such profiling may provide valuable insight into neuromuscular capabilities during growth and maturation and may be used to monitor specific training adaptations.  相似文献   

11.
Touch/control football boots are reportedly designed for optimal passing and dribbling. Little research exists on the effect of boot design on touch/control performance and no validated protocol has been developed for assessing passing and dribbling from an equipment focus. This study aimed to assess the effect of upper padding on dribbling and passing performance using a test–retest reliable test setup. Eight university players performed a protocol of dribbling, short and long passing in football boots with 0 and 6 mm of upper padding (Poron foam). The protocol was completed twice; the 0-mm padding results were used for test–retest validation, while the 0-mm versus 6-mm padding results were used to investigate the effect of padding. Dribbling performance was assessed though completion time, number of touches applied and lateral deviation from cones and passing performance through ball velocity and offset from target. The protocol demonstrated good test–retest reliability and indicated no significant differences in any of the 12 performance variables between the 0- and 6-mm padded boots. These findings suggest an element of design freedom in the use of padding within football boot uppers without affecting dribbling or passing performance.  相似文献   

12.
The present study explored the method of testing muscle mechanical properties through the linear force–velocity (FV) relationships obtained from loaded vertical jumps. Specifically, we hypothesised that the FV relationship parameters depicting the force, power, and velocity of the tested muscles will differ among individuals of different physical fitness. Strength trained, physically active, and sedentary male participants (N = 10 + 10 + 10; age 20–29 years) were tested on maximum countermovement and squat jumps where manipulation of external loads provided a range of F and V data. The observed FV relationships of the tested leg muscles were approximately linear and mainly strong (median correlation coefficients ranged from 0.77 to 0.92; all p < 0.05), independently of either the tested group or the jump type. The maximum power revealed higher values in the strength trained than in the physically active and sedentary participants. This difference originated from the differences in F-intercepts, rather than from the V-intercepts. We conclude that the observed parameters could be sensitive enough to detect the differences among both the individuals of different physical fitness and various jump types. The present findings support using loaded vertical jumps and, possibly, other maximum performance multi-joint movements for the assessment of mechanical properties of active muscles.  相似文献   

13.
Abstract

There has been no previous investigation of the concurrent validity and reliability of the current 5 Hz global positioning system (GPS) to assess sprinting speed or the reliability of integrated GPS–accelerometer technology. In the present study, we wished to determine: (1) the concurrent validity and reliability of a GPS and timing gates to measure sprinting speed or distance, and (2) the reliability of proper accelerations recorded via GPS–accelerometer integration. Nineteen elite youth rugby league players performed two over-ground sprints and were simultaneously assessed using GPS and timing gates. The GPS measurements systematically underestimated both distance and timing gate speed. The GPS measurements were reliable for all variables of distance and speed (coefficient of variation [CV] = 1.62% to 2.3%), particularly peak speed (95% limits of agreement [LOA] = 0.00 ± 0.8 km · h?1; CV = 0.78%). Timing gates were more reliable (CV = 1% to 1.54%) than equivalent GPS measurements. Accelerometer measurements were least reliable (CV = 4.69% to 5.16%), particularly for the frequency of proper accelerations (95% LOA = 1.00 ± 5.43; CV = 14.12%). Timing gates and GPS were found to reliably assess speed and distance, although the validity of the GPS remains questionable. The error found in accelerometer measurements indicates the limits of this device for detecting changes in performance.  相似文献   

14.
15.
16.
Abstract

The aim of this study was to investigate the effect of using poles on foot–ground interaction during trail running with slopes of varying incline. Ten runners ran on a loop track representative of a trail running field situation with uphill (+9°), level and downhill (?6°) sections at fixed speed (3.2 m.s?1). Experimental conditions included running with (WP) and without (NP) the use of poles for each of the three slopes. Several quantitative and temporal foot–ground interaction parameters were calculated from plantar pressure data measured with a portable device. Using poles induced a decrease in plantar pressure intensity even when the running velocity stayed constant. However, the localisation and the magnitude of this decrease depended on the slope situations. During WP level running, regional analysis of the foot highlighted a decrease of the force time integral (FTI) for absolute (FTIabs; ?12.6%; P<0.05) and relative values (FTIrel; ?14.3%; P<0.05) in the medial forefoot region. FTIabs (?14.2%; P<0.05) and duration of force application (Δt; ?13.5%; P<0.05) also decreased in the medial heel region when WP downhill running. These results support a facilitating effect of pole use for propulsion during level running and for the absorption phase during downhill running.  相似文献   

17.
Given that research outside of sport and exercise has found that stigma may cause severe consequences (e.g. depression), it is important to explore the concept in regard to its connection to socio-cultural issues in the development and persistence of stigmatisation in sporting contexts. Analytic autoethnography and Goffman’s theory of stigma was used to explore one female swimmer’s experiences of ‘enacted’ and ‘felt’ competitive performance stigma occurring in elite swimming and a masters swimming context. Competitive performance stigma has not been conceptualised or explored as a stigma type in sport research, however through the presentation and analysis of two vignettes and the use of Goffman, this is achieved. The social agents that contributed to both ‘enacted’ and ‘felt’ competitive performance stigma and the consequences/effects (e.g. withdrawal from sport, feelings of shame) for this swimmer are highlighted. Our analysis further highlights the role of particular cultural insiders (e.g. coaches, team managers and other swimmers) in the reproduction of competitive performance stigma through acts of labelling, discrimination and social isolation. These acts positioned the female swimmer as an ‘outsider’ because of her competitive performance which in turn led to her withdrawal from these two sporting contexts highlighting the implications for recipients of stigmatisation.  相似文献   

18.
BackgroundThe pressure of pursuing an athletic career simultaneously with education may set adolescent student-athletes at risk for sport and school burnout. Although the 2 life domains of student-athletes are strongly intertwined, so far, there has not been an instrument for investigating sport burnout parallel to school burnout. The aim of the present study was to introduce a sport burnout measure for adolescents in a dual career context and investigate its validity and reliability by using confirmatory factor analysis.MethodsThe participants were 391 student-athletes (51% females) who filled in a questionnaire of sport burnout and background variables in the beginning of upper secondary school.ResultsA 3-factor model or a second-order-factor model described the data better and gave better reliability indices than a 1-factor model. The 3 dimensions of sport burnout were shown to be separate, but closely related constructs. Evidence for convergent and discriminant validity was obtained by correlating the 3 sport burnout dimensions with depressive symptoms, self-esteem, and sport task values.ConclusionThe results suggest that Sport Burnout Inventory–Dual Career Form (SpBI-DC) is a valid and reliable instrument for investigating sport burnout among adolescent student-athletes.  相似文献   

19.
Football as a generic game-form was a feature of the sporting culture of the settlers of Australia. As the various codes emerged in Britain they were ‘exported’ to the colonies throughout the Empire. In Australia this cultural imposition was not complete for the British games faced significant cultural resistance, most notably from Australian Rules football. The first formal club was founded circa 1865 and by the time a governing body was formed in 1874, the game had acquired distinctive playing and administrative traits and a sporting ethos, These were aberrant to the British form as pragmatic modifications were made in response to the social, cultural and environmental exigencies and demands of the frontier-like context: the game of Rugby immediately became Australianized. This analysis traces the development of the game's culture in Australia through the initial 75 years of its institutionalization and demonstrates that despite its transit through the colonial era, urbanization, nationalism, federation and the travails of two World Wars, aspects of the residual culture remained. Rugby football, established in NSW and Queensland as a feature of the cultural hegemony of British Imperialism, prevailed largely unchanged in terms of power relations, ideology, finances and success over its first 75 years. This discussion reflects upon the critical influences, incidents and individuals that impacted upon and shaped Rugby union football in NSW and Queensland up to the founding of the Australian Rugby Football Union, which took until 1949 to occur.  相似文献   

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