Identifying and developing rugby talent among 10-year-old boys: a practical model

The re-entry of South Africa into the international sporting arena and the resultant need for the identification and development of talent, especially among formerly deprived groups of people, provided the incentive for this study. Its aim was to identify the physical, motor and anthropometric variables that will enable coaches to identify 10-year-old boys, based on their abilities, who could become successful rugby players. Altogether, 173 ten-year-old boys with no rugby experience from a cross-section of the population were selected at random and subjected to 14 physical and motor tests and 14 anthropometric measurements. From 22 schools which participated in the Western Transvaal primary schools under-11 rugby league, the three top teams (n = 45 individuals) were selected and also tested. The results from these three teams were used as the criteria for rugby talent among 10-year-old boys. To establish the best predictors of talent, a stepwise discriminant analysis was conducted: this indicated eight variables (four motor and four anthropometric) that discriminated maximally between the talented and the rest of the players of this age. With classification functions based on these eight variables, 93.8% of all the subjects were classified correctly, indicating good validity. A canonical analysis, based on the selected variables, was then conducted on all the under-11 teams that played in the league in the region (n = 330), and they were ranked according to the scores of the first canonical variable from the most to the least talented. By comparing these results with the players who were chosen for the region's primary schools team, a success rate of 88% in prediction of talent was established. We conclude that this is a successful and practical method to aid the teacher and the coach in selecting and developing talent among 10-year-old rugby players in South Africa.     

Identifying and developing rugby talent among 10-year-old boys: A practical model

The re-entry of South Africa into the international sporting arena and the resultant need for the identification and development of talent, especially among formerly deprived groups of people, provided the incentive for this study. Its aim was to identify the physical, motor and anthropometric variables that will enable coaches to identify 10-year-old boys, based on their abilities, who could become successful rugby players. Altogether, 173 ten-year-old boys with no rugby experience from a cross-section of the population were selected at random and subjected to 14 physical and motor tests and 14 anthropometric measurements. From 22 schools which participated in the Western Transvaal primary schools under-11 rugby league, the three top teams (n = 45 individuals) were selected and also tested. The results from these three teams were used as the criteria for rugby talent among 10-year-old boys. To establish the best predictors of talent, a stepwise discriminant analysis was conducted: this indicated eight variables (four motor and four anthropometric) that discriminated maximally between the talented and the rest of the players of this age. With classification functions based on these eight variables, 93.8% of all the subjects were classified correctly, indicating good validity. A canonical analysis, based on the selected variables, was then conducted on all the under-11 teams that played in the league in the region (n = 330), and they were ranked according to the scores of the first canonical variable from the most to the least talented. By comparing these results with the players who were chosen for the region's primary schools team, a success rate of 88% in prediction of talent was established. We conclude that this is a successful and practical method to aid the teacher and the coach in selecting and developing talent among 10-year-old rugby players in South Africa.     

Objectively measured physical activity,body composition and physical fitness: Cross-sectional associations in 9- to 15-year-old children

The aim of this study was to examine and quantify the cross-sectional associations of body composition (BC), physical activity (PA) and sedentary time (ST) with physical fitness (PF) in children and adolescents. A sample of 594 Finnish students (56% girls), aged 9–15 (12.4?±?1.3 years) were selected for a study performed in 2013. The measurements of the Move! monitoring system for physical functional capacity were used to measure cardiorespiratory and musculoskeletal fitness and fundamental movement skills. Moderate-to-vigorous PA (MVPA) and ST were measured objectively with an accelerometer and BC by a bioelectrical impedance analysis. Fat mass index (FMI) and fat-free mass index (FFMI) were calculated to represent height-adjusted BC. Associations were explored with a linear regression model. In general, FMI had statistically significant negative associations, while FFMI and MVPA had positive associations with PF. No statistically significant associations were observed between ST and PF. In general, FMI had the strongest association with PF, although some variation occurred with sex and PF component. However, associations were practically relevant only in 20-m shuttle run, push-up, curl-up and 5-leaps test. For example, approximately 5?kg increase in fat mass in 155?cm tall children was estimated to correspond to 8 laps in 20-m shuttle run. Similar increase in fat-free mass corresponded to +4 and +6 laps, and 10?min increase in daily MVPA +3 and +2 laps in 20-m shuttle run, in boys and girls, respectively. Understanding these associations is necessary when interpreting children’s PF and designing interventions.     

Comparison of accelerometer and pedometer measures of physical activity in boys and girls, ages 8-10 years

Accelerometers record total physical activity and time spent at different intensities. Pedometers indicate total activity only. The aim of this study was to assess the relationship between pedometer counts and attainment of > or = 60 min of moderate activity. Thirty-four children, ages 8-10 years, wore a Tritrac accelerometer and Yamax pedometer. Published recommendations of steps per day were compared to attainment of > or = 60 min moderate activity. Boys who accumulated 13,000 steps.d(-1) and girls who accumulated 12,000 steps.d(-1) engaged in > or = 60 min moderate activity. However, 23% of boys and 15% of girls did not reach the pedometer thresholds but did engage in > or = 60 min moderate activity. In conclusion, these pedometer thresholds provide a reasonable estimation when assessment of physical activity intensity is not possible.     

Evaluation of low-cost, objective instruments for assessing physical activity in 10-11-year-old children

This study compared step counts detected by four, low-cost, objective, physical-activity-assessment instruments and evaluated their ability to detect moderate-to-vigorous physical activity (MVPA) compared to the ActiGraph accelerometer (AG). Thirty-six 10-11-year-old children wore the NL-1000, Yamax Digiwalker SW 200, Omron HJ-151, and Walk4Life MVP concurrently with the AG during school hours on a single day. AG MVPA was derived from activity count data using previously validated cut points. Two of the evaluated instruments provided similar group mean MVPA and step counts compared to AG (dependent on cut point). Low-cost instruments may be useful for measurement of both MVPA and steps in children's physical activity interventions and program evaluation.     

The validity and reliability of a sample of 10 Wattbike cycle ergometers

ABSTRACT

The purpose of the study was to assess the validity and inter-bike reliability of 10 Wattbike cycle ergometers, and to assess the test–retest reliability of one Wattbike. Power outputs from 100 to 1000 W were applied using a motorised calibration rig (LODE) at cadences of 70, 90, 110 and 130 rev · min^?1, which created nineteen different intensities for comparison. Significant relationships (P < 0.01, r² = 0.99) were found between each of the Wattbikes and the LODE. Each Wattbike was found to be valid and reliable and had good inter-bike agreement. Within-bike mean differences ranged from 0.0 W to 8.1 W at 300 W and 3.3 W to 19.3 W at 600 W. When taking into account the manufacturers stated measurement error for the LODE (2%), the mean differences were less than 2%. Comparisons between Wattbikes at each of the nineteen intensities gave differences from 0.6 to 25.5 W at intensities of 152 W and 983 W, respectively. There was no significant difference (P > 0.05) between the measures of power recorded in the test–retest condition. The data suggest that the Wattbike is an accurate and reliable tool for training and performance assessments, with data between Wattbikes being able to be used interchangeably.     

Cardiovascular fitness in obese versus nonobese 8-11-year-old boys and girls

The purpose of this study was to compare cardiovascular fitness between obese and nonobese children. Based on body mass index, 118 were classified as obese (boys [OB] = 62, girls [OG] = 56), while 421 were nonobese (boys [NOB] = 196, girls [NOG] = 225). Cardiovascular fitness was determined by a 1-mile [1.6 km] run/walk (MRW) and estimated peak oxygen uptake (VO2peak) and analyzed using two-way analyses of variance (Gender x Obese/Nonobese). MRW times were significantly faster (p < .05) for the NOB (10 min 34 s) compared to the OB (13 min 8 s) and the NOG (13 min 15 s.) compared to the OG (14 min 44 s.). Predicted VO2peak values (mL x kg(-1) x min(-1)) were significantly higher (p < .05) for the NOB (48.29) compared to the OB (41.56) and the NOG (45.99) compared to the OG (42.13). MRW was compared between obese and nonobese participants on the President's Challenge (2005), the National Children and Youth Fitness Study, and FITNESSGRAM HFZ standards. The nonobese boys and girls scored higher on all three, exhibiting better cardiovascular fitness as compared to obese counterparts.     

A single bout of high-intensity interval exercise and work-matched moderate-intensity exercise has minimal effect on glucose tolerance and insulin sensitivity in 7- to 10-year-old boys

The purpose of this study was to assess the acute effect of high-intensity interval exercise (HIIE) and moderate-intensity exercise (MIE) on glucose tolerance, insulin sensitivity and fat oxidation in young boys. Eleven boys (8.8 ± 0.8 y) completed three conditions: 1) HIIE; 2) work-matched MIE; and 3) rest (CON) followed by an oral glucose tolerance test (OGTT) to determine glucose tolerance and insulin sensitivity (Cederholm index). Fat oxidation was measured following the OGTT using indirect calorimetry. There was no effect for condition on plasma [glucose] and [insulin] area under the curve (AUC) responses following the OGTT (P > 0.09). However, there was a “trend” for a condition effect for insulin sensitivity with a small increase after HIIE (P = 0.04, ES = 0.28, 9.7%) and MIE (P = 0.07, ES = 0.21, 6.5%) compared to CON. There was an increase in fat oxidation AUC following HIIE (P = 0.008, ES = 0.79, 38.9%) compared to CON, but with no differences between MIE and CON and HIIE and MIE (P > 0.13). In conclusion, 7- to 10-year-old boys may have limited scope to improve insulin sensitivity and glucose tolerance after a single bout of HIIE and MIE. However, fat oxidation is augmented after HIIE but not MIE.     

The reliability and validity of the 20-meter shuttle test in American students 12 to 15 years old.

The purpose of this study was threefold: to determine (a) the test-retest reliability of the 20-m shuttle test (20 MST) (number of laps), (b) the concurrent validity of the 20 MST (number of laps), and (c) the validity of the prediction equation for VO2max developed by Léger, Mercier, Gadoury, and Lambert (1988) on Canadian children for use with American children 12-15 years old. An intraclass coefficient of .93 was obtained on 20 students (12 males; R = .91 and 8 females; R = .87) who completed the test twice, 1 week apart (MT1 = 47.80 +/- 20.29 vs. MT2 = 50.55 +/- 22.39 laps; p > or = .13). VO2peak was obtained by a treadmill test to volitional fatigue on 48 subjects. The number of laps run correlated significantly with VO2peak in males (n = 22; r = .65; F [1, 20] = 14.30 p < or = .001), females (n = 26; r = .51; F [1, 24] = 8.34; p < or = .01), and males and females = (r = .69; F [1, 46] = 42.54, p < or = .001). When the measured VO2peak (M = 49.97 +/- 7.59 ml.kg-1.min-1) was compared with the estimated VO2max (M = 48.72 +/- 5.72 ml.kg-1.min-1) predicted from age and maximal speed of the 20 MST (Léger et al., 1988) no significant difference was found, t (47) = -1.631; p > or = .11, between the means; the r was .72 and SEE was 5.26 ml.kg-1.min-1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Translation,cross-cultural adaptation,validity, reliability and stability of the Dutch Injury - Psychological Readiness to Return to Sport (I-PRRS-NL) scale

The Injury Psychological Readiness to Return to Sport (I-PRRS) scale measures the psychological readiness of injured athletes to resume sports participation. The aim of this study was to translate and culturally adapt the I-PRRS scale into Dutch (I-PRRS-NL) and assess its validity, reliability, and stability in patients after anterior cruciate ligament reconstruction (ACLR). The original I-PRRS was translated and culturally adapted from English into Dutch, and tested for clinimetric quality. To assess concurrent validity, 150 patients completed the I-PRRS-NL scale and five questionnaires measuring related constructs 3–16 months after ACLR. All predefined hypotheses regarding correlations between the I-PRRS-NL scale and these questionnaires were confirmed, indicating good concurrent validity. For test-retest reliability, 107 patients completed the I-PRRS-NL scale again two weeks later. The I-PRRS-NL scale showed good internal consistency (Cronbach’s alpha 0.94) and test-retest reliability (ICC 0.89). Standard error of measurement was 4.2 and smallest detectable change was 11.6. No systematic bias between test and retest was found. As the scale appears unstable at item level, only the total score should be used. Overall, the I-PRRS-NL scale showed sufficient validity and reliability to assess the psychological readiness to resume sports among Dutch-speaking patients after ACLR.     

Reliability and validity of Yo-Yo tests in 9- to 16-year-old football players and matched non-sports active schoolboys

The purpose of this study was to examine the test–retest reliability and construct validity of three age-adapted Yo-Yo intermittent tests in football players aged 9–16 years (n?=?70) and in age-matched non-sports active boys (n?=?72). Within 7 days, each participant performed two repetitions of an age-related intensity-adapted Yo-Yo intermittent test, i.e. the Yo-Yo intermittent recovery level 1 children's test for 9- to 11-year-olds; the Yo-Yo intermittent endurance level 1 for 12- to 13-year-olds and the Yo-Yo intermittent endurance level 2 test for 14- to 16-year-olds. Peak heart rate (HR_peak) was determined for all tests. The distance covered in the tests was 57% (1098?±?680 vs. 700?±?272?m), 119% (2325?±?778 vs. 1062?±?285?m) and 238% (1743?±?460 vs. 515?±?113?m) higher (p?≤?.016), respectively for football-trained than for non-sports active boys aged 9–11, 12–13 and 14–16 years. The typical errors of measurement for Yo-Yo distance, expressed as a percentage of the coefficient of variation (confidence interval), were 11.1% (9.0–14.7%), 10.1% (8.1–13.7%) and 8.5% (6.7–11.7%) for football players aged 9–11, 12–13 and 14–16 years, respectively, with corresponding values of 9.3% (7.4–12.8%), 10.2% (8.1–14.0%) and 8.5% (6.8–11.3%) for non-sports active boys. Intraclass correlation coefficient values for test–retest were excellent in both groups (range: 0.844–0.981). Relative HR_peak did not differ significantly between the groups in test and retest. In conclusion, Yo-Yo intermittent test performances and HR_peak are reliable for 9- to 16-year-old footballers and non-sports active boys. Additionally, performances of the three Yo-Yo tests were seemingly better for football-trained than for non-sports active boys, providing evidence of construct validity.     

Validity of an Athletic Skills Track among 6- to 12-year-old children

The purpose of this study was to examine the feasibility and validity of an Athletic Skills Track (AST) to assess fundamental movement skills among 6- to 12-year-old children in a physical education setting. Four hundred sixty-three Dutch children (211 girls, 252 boys) completed three tests: the Körperkoordinationstest für Kinder (KTK) and two Athletic Skills Tracks (AST-1, AST-2). The validity of AST-1 and AST-2 was examined by correlating the time (s) needed to complete the tracks and the KTK Motor Quotient (MQ).

Overall, there was a low correlation between AST-1 and the KTK MQ (r = –0.474 (P < 0.01)) and a moderate correlation between AST-2 and the KTK MQ (r = –0.502 (P < 0.01)). When split up by age group the associations were much higher and ranged between r = –0.469 and r = –0.767), with the exception of the low correlation coefficient of the AST-2 in 7-year-olds. The results indicate that fundamental movement skills of 6- to 12-year-old children can be assessed with a quick, convenient and low-cost motor competence test in a physical education setting, i.e., an Athletic Skills Track. Future studies should further assess the reliability, discriminative ability and validity of age-specific versions of the AST.     

Progressive aerobic cardiovascular endurance run and body mass index among an ethnically diverse sample of 10-15-year-olds

This study examined the cardiovascular fitness (CVF, Progressive Aerobic Cardiovascular Endurance Run [PACER], number of laps completed) and the prevalence of at risk of overweight (AR) and overweight (OW) among 10-15-year-olds (48% girls)from the following ethnic backgrounds: African American (n = 2,604), Asian-Pacific Islander (n = 3,888), Hispanic (n = 11,680); and White non-Hispanic (n = 16,352). Hierarchal multiple linear regression analysis, controlling for height and weight, with White non-Hispanics serving as the comparison group, revealed a limited number of significant differences among PACER performances, with no values exceeding +/- 4.43 laps. Odds ratios (OR) for being classified as AR or OW were significantly greater (p < .01) in African American (OR = 1.25, 1.65) and Hispanic (OR = 2.33, 2.28) boys and girls, respectively, and Asian boys (OR = 1.43). The results of this cross-sectional analysis indicated negligible differences in CVF among ethnic groups, while AR and OW were consistent with previous reports for ethnic populations.     

Functional capacities and sport-specific skills of 14- to 15-year-old male basketball players: Size and maturity effects

Abstract

The aim of the study was to estimate the influence of body size and pubertal status on variation in functional capacities and sport-specific skills of 59 youth basketball players aged 14.0–15.9 years. Height and mass were measured and stage of pubic hair was assessed at clinical examination. Six tests of functional capacity were evaluated: squat jump, countermovement jump, 60-s sit-ups, 2-kg standing medicine ball throw, hand grip strength, and 20-m multi-stage shuttle run. Four basketball skills were tested (shooting, passing, dribbling, and defensive movements). Comparisons between basketball players of different sexual maturity status were performed using analysis of covariance (controlling for chronological age). Functional capacities and basketball skills appeared to be largely independent of pubertal status especially after controlling for variation in body size. Results of multiple linear regressions indicated chronological age as a significant predictor for four items, while maturity status was a significant predictor for only one item. The influence of body mass was negative for two functional indicators (jumping, multi-stage shuttle run) and two basketball skills (dribbling, defensive movements), but positive for two functional tests of upper body strength (hand grip, ball throw). Height was positively correlated with two specific skills (passing, defensive movements), while a combination of tallness and heaviness was associated with a disadvantage on three functional capacities and two sport-specific skills.     

Patterns of physical activity and overweight among 7-13-year-old Russian children: a 7-year nationally representative monitoring study

This is a repeated cross-sectional study of overweight and physical activity (PA) and inactivity patterns of successive samples of 7-13-year-old Russian children who were surveyed six times between 1995 and 2002 as part of the Russian Longitudinal Monitoring Survey. This analysis focused on moderate/vigorous (MOD/VIG) PA (e.g., active commuting to school, during school MOD/VIG PA as part of physical education classes, and/or before/after school MOD/VIG PA) and inactivity patterns (e.g, television viewing habits) obtained through parent proxy-reports of 3,507 boys (M age = 10.1 years, SD = 2.0; body mass index = 17.5 kg/m2, SD = 3.0) and 3,273 girls (M age = 10.1 years, SD = 2.0; body mass index = 17.2 kg/m2, SD = 3.0). Time spent in MOD/VIG PA appears to be on the rise, while the proportion of those actively commuting to school is decreasing, especially among girls.     

Factorial validity and invariance of a self-report measure of physical activity among adolescent girls

We examined the factorial validity and factorial invariance of the 3-day physical activity recall (3DPAR) using confirmatory factor analysis. Adolescent girls from two cohorts (N = 955, N = 1,797) completed the 3DPAR in the eighth grade; participants in Cohort 2 (N = 1,658) completed the 3DPAR again 1 year later in the ninth grade. The 3DPAR was best represented by two uncorrelated factors in Cohort 1. The two-factor, uncorrelated measurement model exhibited evidence of cross-validity between Cohorts 1 and 2. This model also exhibited configural and partial metric invariance between race and across time. Hence, the 3DPAR consisted of two uncorrelated factors underlying three indicators of both moderate and vigorous physical activity in this sample of Black and White girls across a 1-year period. The 3DPAR can be used in cross-sectional, prospective cohort and intervention studies that examine mediators and moderators of physical activity among Black and White adolescent girls.     

Reliability and concurrent validity of a motor skill competence test among 4- to 12-year old children

The purpose of this study was to examine the test-retest reliability, internal consistency and concurrent validity of the Athletic Skills Track (AST). During a regular PE lesson, 930 4- to 12-year old children (448 girls, 482 boys) completed two motor skill competence tests: (1) the Körperkoordination-Test für Kinder (KTK) and (2) an age-related version of the AST (age 4–6 years: AST-1, age 6–9 years: AST-2, and age 9–12 years: AST-3). The test-retest reliability of the AST was high (AST-1: ICC = 0.881 (95% CI: 0.780–0.934); AST-2: ICC = 0.802 (95% CI: 0.717–0.858); and AST-3: ICC = 0.800 (95% CI: 0.669–0.871). The internal consistency, concerning the three age-bands of the AST was above the acceptable level of Cronbach’s α > 0.70 (AST-1: α = 0.764; AST-2: α = 0.700; and AST-3: α = 0.763). There was a moderate to high correlation between the time to complete the AST, and the age- and gender-related motor quotients of the KTK (AST-1: r = ?0.747, p = 0.01; AST-2: r = ?0.646, p = 0.01; and AST-3: r = ?0.602, p = 0.01). The Athletic Skills Track is a reliable and valid assessment tool to assess motor skill competence among 4- to 12-year old children in the PE setting.     

高校体育教师心理契约量表的编制与信效度检验

通过访谈法、问卷调查法、文献资料法、数理统计法,编制高校体育教师心理契约问卷,运用探索性因子分析进行因子提取和命名,用验证性因子分析进行了验证,分半信度和内部一致性信度显示符合量表编制信度要求。结果显示,高校体育教师心理契约问卷包括两个部分:高校体育教师心理契约学校责任问卷包括三个维度:经济与环境责任、成长责任和人文责任;高校体育教师心理契约教师责任问卷包括四个维度:课外责任、岗位责任、归属责任和社会责任。     

Effects of a 12-week physical activity protocol delivered by YMCA after-school counselors (Youth Fit for Life) on fitness and self-efficacy changes in 5-12-year-old boys and girls

To address reduced physical education (PE) in elementary schools, a 12-week physical activity protocol was tested on 5-12-year-old, primarily African American, girls (n = 226) and boys (n = 344) at 14 YMCA after-school care sites. The 3 times/week, 45-min session curriculum included cardiovascular, resistance, and flexibility training, in which all children could participate simultaneously, and a behavioral skills education component. After-school counselors, formerly untrained in PE methods, administered the sessions, with periodic supervision by YMCA wellness staff members. Analyses of the eight Age x Sex subsamples indicated significant improvements on body composition, strength, and endurance, both within-groups and when predicted changes due to maturation were accounted for. Exercise barriers self-efficacy significantly increased in subsamples of 9-10- and 11-12-year-old girls only. The need for replication across ethnic groups was suggested. Limitations and the need for extension of research on supplementation of elementary school PE were discussed.