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1.
Abstract The purpose of this study was to examine the adequacy of “multi-age” classification systems in youth sports with a specific focus on the unisex multi-age-groupings used by USA Swimming. In addition, we offer an analytical rationale for the multi-age-groupings and potential alternatives. We examined the top 100 US swim performances for three years (2005, 2006, and 2007) for girls and boys in 15 age-groups (7 to 20 years and a singular group of 21 years and older). Data for each age and sex were pooled over the three years and means were calculated for each of seven competitive swim events. Swim times differed among each age up to the 14-year age-group in girls (F 14,30885 = 183.9, P < 0.01, Cohen's d = 1.19–3.72, large effect) and 16-year age-group in boys (F 14,30885 = 308.7, P < 0.01, Cohen's d = 0.81–3.64, large effect) for all events. Age-related differences in swim times continued later in boys than girls likely due to differences between the sexes in timing of growth and maturation. Because of the differences in swim performance in contemporary multi-age-groups, stratifying swimmers by a single age is the best means to ensure competitive fairness and equality, although there is no rationale for swimmers under the age of 8 years to compete in separate unisex competitive groups. 相似文献
2.
We examined the supposition that swimmers may exhibit an imbalance in bilateral arm power output during simulated swimming exercise. Ten competitive front crawl swimmers (5 males, 5 females; age 20.5+/-2.3 years; height 1.74+/-0.09 m; body mass 72.0+/-16.7 kg; 400 m freestyle swim time 278+/-20.5 s; mean +/- s) performed four incremental (10 W x min(-1)) swim ramp tests on a computer-interfaced biokinetic swim bench ergometer. External power output from each arm was measured continuously to exhaustion. The results showed that, throughout the course of the simulated swim, external power output clearly favoured the left arm (F1,9 = 12.5, P= 0.006). This was especially evident in the final 30 s to exhaustion, when 54.0+/-3.87% of external power output was derived from the left arm versus 46.0+/-3.87% from the right arm. The disparity in external power output was further highlighted when the participants were grouped into unilateral and bilateral breathers. Unilateral breathers (n = 5) produced 57.1+/-2.62% of external power output from the left armversus 42.9+/-2.62% from the right arm (P= 0.001). Bilateral breathers (n = 5) exhibited a more balanced external power output of 51.0+/-1.82% from the left arm and 49.0+/-1.82% from the right arm (P = 0.177). Evidence of power imbalance in the simulated swimming stroke may have important implications for optimizing swim performance. The observed power imbalance may be reduced when a bilateral breathing technique is adopted. 相似文献
3.
Shaun Abbott Kylie Moulds James Salter Michael Romann Lucy Edwards 《Journal of sports sciences》2020,38(10):1077-1084
ABSTRACT The purpose of this study was (1) accurately estimate longitudinal relationships between decimal age (i.e., chronological and relative) and performance in Australian female 100 m (N = 765) and 200 m (N = 428) Breaststroke swimmers (10–18 years); and (2) determine whether corrective adjustment procedures could remove Relative Age Effects (RAEs) in an independent sample of age-matched 100 m (N = 2,491) and 200 m (N = 1,698) state/national level Breaststroke swimmers. In Part 1, growth curve modelling quantified longitudinal relationships between decimal age and swimming performance. In Part 2, relative age distributions (Quartile 1–4) for “All”, “Top 25%” and “10%” of swimming times were examined based on raw and correctively adjusted swim times for age-groups. Based on raw swim times, finding identified RAE effect sizes increased in magnitude (small-medium) with selection level (“All”-“Top 25%”) in 12–14 years age-groups for both events. However, when correctively adjusted swim performances were examined, RAEs were primarily absent across all age-groups and selection levels. Using longitudinal reference data, corrective adjustment procedures removed relative age advantages in female youth Breaststroke performance. Removing the influence of relative age-related differences is predicted to improve the accuracy of identifying genuinely skilled youth swimmers. 相似文献
4.
To determine the relationship between prescribed training and seasonal-best swimming performance, we surveyed 24 swim coaches and 185 of their age-group and open-class swimmers specializing in sprint (50 and 100 m) and middle-distance (200 and 400 m) events in a summer and winter season. We expressed effects on training as either multiples of swimmers' standard deviations (effect size, ES) or as correlations (r). Coaches prescribed higher mileage and longer repetitions of lower intensity to middle-distance swimmers than to sprinters (ES = 0.4-1.5); as competitions approached, repetition intensity and duration of rest intervals increased (ES = 0.5-0.9), whereas session and repetition distances decreased (ES = 0.4-1.3). The 95% likely ranges of the true values for these effects were about +/- 0.3. Weekly mileage swum at an easy or moderate pace remained at almost 60% of the total throughout both seasons. Interval training reduced gradually from 40% of total distance in the build-up to 30% at the end of tapering. Older swimmers had shorter rests and swam more miles (r = 0.5-0.8). After partialling out the effects of age on performance (r = 0.7-0.8), better performance was significantly associated only with greater weekly mileage (r = 0.5-0.8) and shorter duration of rest intervals (r = 0.6-0.7) in middle-distance swimmers. We conclude that periodization of training and differences in training between sprint and middle-distance events were broadly in accord with principles of specificity. Strong effects of specificity on performance were not apparent, but weak effects might have been detected with a larger sample. 相似文献
5.
To determine the relationship between prescribed training and seasonal-best swimming performance, we surveyed 24 swim coaches and 185 of their age-group and open-class swimmers specializing in sprint (50 and 100 m) and middle-distance (200 and 400 m) events in a summer and winter season. We expressed effects on training as either multiples of swimmers' standard deviations (effect size, ES) or as correlations ( r ). Coaches prescribed higher mileage and longer repetitions of lower intensity to middle-distance swimmers than to sprinters (ES = 0.4-1.5); as competitions approached, repetition intensity and duration of rest intervals increased (ES = 0.5-0.9), whereas session and repetition distances decreased (ES = 0.4-1.3). The 95% likely ranges of the true values for these effects were about - 0.3. Weekly mileage swum at an easy or moderate pace remained at almost 60% of the total throughout both seasons. Interval training reduced gradually from 40% of total distance in the build-up to 30% at the end of tapering. Older swimmers had shorter rests and swam more miles ( r = 0.5-0.8). After partialling out the effects of age on performance ( r = 0.7-0.8), better performance was significantly associated only with greater weekly mileage ( r = 0.5-0.8) and shorter duration of rest intervals ( r = 0.6-0.7) in middle-distance swimmers. Weconclude that periodization of training and differences in training between sprint and middle-distance events were broadly in accord with principles of specificity. Strong effects of specificity on performance were not apparent, but weak effects might have been detected with a larger sample. 相似文献
6.
Much research has examined shoulder range of motion adaptations in overhead-unilateral athletes. Based on the void examining overhead-bilateral athletes, especially competitive swimmers, we examined shoulder external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion of competitive swimmers. The range of motion of registered competitive swimmers (n = 144, age = 12-61 years) was compared by limb (dominant, non-dominant), sex, and age group (youth, high school, college, masters). Significantly (P < 0.05) greater dominant external rotation was observed for both men and women high school and college swimmers, youth women swimmers, and men masters swimmers compared with the non-dominant limb. The isolated internal rotation (glenohumeral rotation), composite internal rotation (glenohumeral rotation plus scapulothoracic protraction), and total arc of motion (external rotation plus composite internal rotation) of the non-dominant limb was significantly greater than that of the dominant limb by sex and age group. Youth and high school swimmers demonstrated significantly greater composite internal rotation than college and masters swimmers. Youth swimmers displayed significantly greater total arc of motion than all other age groups. These data will aid in the interpretation of shoulder range of motion values in competitive swimmers during preseason screenings, injury evaluations and post-rehabilitation programmes, with the results suggesting that differences exist in bilateral external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion. 相似文献
7.
Abstract Few studies of young competitive swimmers have measured the swimmer in the water, but many have utilized the treadmill or bicycle ergometer on land. The maximum oxygen uptake of 31 (17 male and 14 female) competitive swimmers, 9 to 17 years of age, was determined during an intermittent tethered swimming test which consisted of a series of 3-minute workloads followed by 3-minute rest intervals. Each new workload was increased by multiples of 1.1 kg, and the work was continued to voluntary exhaustion. The subjects were members of a competitive swim club that took part in vigorous swim training throughout the year. Testing was conducted at the peak of the competitive out-door season. Over a period of a year, the daily training distance of these swimmers averaged approximately 7,000 yards, or almost four times that reported by others. The mean maximum oxygen uptake was 48.8 ml·kg?1·min?1 for the females and 55.8 ml·kg?1·min?1 for the males. Although the values for the younger swimmers were comparable with other published studies, the older male and female swimmers exhibited consistently higher values. The natural decline in maximum oxygen uptake per unit weight (ml/kg) reported by others in pubescent females was reversed by the over-distance training in the present study. 相似文献
8.
Recent international normative data for the 20-m shuttle-run test demonstrated a below-average performance index for UK children. The aims of the present study were to create an international comparison of 20-m shuttle-run test performance in a sample of English children and to identify age- and sex-specific differences in test performance. Mass, stature, body mass index, and 20-m shuttle-run test performance were measured in 2041 children aged 11-15 years (963 boys, 1078 girls). Performance was expressed as maximum running velocity and a performance index was created by generating z-scores. The shuttle-run test performance index was higher than the existing published value (-0.046, 95% confidence interval [CI] -0.070 to -0.022) for all children (0.061, 95% CI = 0.006 to 0.115), for boys (0.075, 95% CI = -0.022 to 0.171), and for girls (0.048, 95% CI = -0.010 to 0.106). Boys' relative performance increased significantly (F = 4.43, P = 0.002) throughout the measured age range, whereas girls' relative performance tended to decrease (F = 1.98, P = 0.096). The results were favourable when compared with existing values. Differences in performance index may be due to the different geographical areas from which present and past samples were drawn. Reasons for differences in the performance indices between boys and girls warrant further investigation. 相似文献
9.
McMurray RG Harrell JS Bradley CB Deng S Bangdiwala SI 《Research quarterly for exercise and sport》2003,74(2):143-152
This study determined gender and ethnic differences in physical work capacity (PWC170) of 8-16-year-old American youth as they progress from elementary to high school. A multicohort group of 2,540 youth participated 50.4% girls (21.4% African Americans, and 78.6% Caucasians). PWC170 was predicted from cycle ergometer testing six times over a 7-year period. The absolute PWC170 of girls stabilized in early adolescence, while boys increased with each trial. The PWC170 relative to body weight of girls decreased steadily, whereas the boys remained stable. African Americans had greater absolute PWC170 values than Caucasians (p = .0001). The relative PWC170 was lower for African American girls than Caucasian girls (p = .0001), but there were no ethnic differences for boys (p > .05). Although correlations and grouping suggested moderate tracking; girls with high relative PWC170 tended to migrate to lower levels as they aged, where as high-peforming boys maintained their PWC170 as they aged. 相似文献
10.
《European Journal of Sport Science》2013,13(5):437-444
Abstract The aim of this study was to analyse the relative age effect (RAE) in competitive swimming. The best 50 Portuguese swimmers (12- to 18-year-olds) for the main individual swimming pool events of both genders were considered. Analysis was conducted on 7813 swimming event participants, taking account of respective swimmer birth dates and the Fédération Internationale de Natation points gained. Differences in the distribution of birth dates by quarter year were determined using the Chi-square. A one-way analysis of variance ANOVA was used to test for differences measured in points between individuals by quarterly birth year intervals. A two-way analysis of variance ANOVA was also conducted to test the interaction between gender and seasonal birth date with regard to performance. The results show an inequitable distribution (p<0.01) of birth dates by quarter for almost all age groups and both genders. However, the distribution of birth dates by quarter for each considered swim event shows that RAE seems to exist only for 12-year-old females and 12- to 15-year-old males. Analysing mean swimming performance, post-hoc results (p<0.01) show no consistency in RAE. Higher performance occurs among older swimmers only in 100 m butterfly (female 1998, 1st≠2nd quarter, p=0.003). The results also show no interaction between gender and seasonal birth date (p<0.01). Findings of this study show that a higher number of swimmers, particular males, are born in the first two quarters of the year, although there is mostly no effect of seasonal birth date on performance differences within the top 50 swimmers. 相似文献
11.
12.
《Measurement in physical education and exercise science》2013,17(1):45-55
The purpose of this study was to examine the validity and reliability of the Cooper 12-min swim test in high school male swimmers ages 13 to 17. Thirty-three boys performed three 12-min swims and 1 maximal graded treadmill test within a 14-day period. One practice swim was conducted 1 week prior to participation in this study. VO2max was assessed by indirect calorimetry with open-circuit spirometry with the Truemax 2400 metabolic cart (Consentius Technologies, Sandy, UT). Test-retest reliability of the 12-min swim assessed via 1-way analysis of variance indicated moderate reliability (R = .66, 95% confidence interval [CI] = .42-.81), whereas concurrent validity assessed via a Pearson product-moment correlation indicated a moderate relation (r = .47, 95% CI = .15-.70, r2 = .22). Results indicate that the Cooper 12-min swimming test is only moderately reliable after 2 practice swims and does not appear to be a valid field test of aerobic capacity in high school male swimmers ages 13 to 17. 相似文献
13.
Stephen Behan Sarahjane Belton Cameron Peers Noel E O’Connor Johann Issartel 《Journal of sports sciences》2013,31(22):2604-2612
ABSTRACTFundamental movement skills (FMS) are the basic building blocks of more advanced, complex movements required to participate in physical activity. This study examined FMS proficiency across the full range of Irish primary school children (n = 2098, 47% girls, age range 5–12 years). Participants were assessed using the Test of Gross Motor Development, 3rd edition (TGMD-3), Victorian Fundamental Movement skills manual, and the balance subtest from the Bruininks-Oseretsky Test of Motor Proficiency 2 (BOT-2). Independent sample t-tests and a one way between groups ANOVA with planned comparisons were used analyse sex and age differences. Mastery or near mastery of skills ranged from 16% for overhand throw, to 75.3% for run. Girls scored significantly higher than boys in the locomotor and balance subtests with the boys outperforming the girls in object control skills. Improvements in ability can be seen over time (F(8,1968) = 70.18, p < 0.001), with significant increases in FMS proficiency seen up to the age of 10, after which proficiency begins to decline. The findings demonstrate the low levels of FMS proficiency amongst Irish primary school children, the differences between sex that exist, and highlights the need for more programmes that focus on developing these FMS at an early age. 相似文献
14.
《Measurement in physical education and exercise science》2013,17(4):263-267
This study was designed to examine the reliability of peak finger force during 4-finger curling in a sample of expert level young competitive rock climbers. The participants (N = 31; 16 boys, 15 girls; 13.0 ± 2.7 years of age) completed 2 maximal finger curls with each hand. Finger force was measured via a piezoelectric force sensor fitted with a plate to accept the first digits of the 4 fingers. Force was applied to the plate/sensor by the fingers via a 3-sec maximal contraction. Reliability of the finger curl for each hand was estimated using a one-way repeated measure analysis of variance (ANOVA) and intraclass test-retest correlation. Reliability of the measurement for the left hand was estimated at R = .947 (.95 confidence interval, .891-.975). Reliability for the right hand was estimated at R = .902 (.95 confidence interval, .796-.953). No significant ( p > .05) differences were found between the 2 trials for either hand. Peak force measurement during maximal finger curls using this protocol and population was judged to be reliable. 相似文献
15.
Kinematic differences between front crawl sprint and distance swimmers at a distance pace 总被引：1，自引：1，他引：0
The purpose of the study was to determine whether there are differences in kinematics between sprint and distance front crawl specialists when swimming at a distance pace using a six beat kick. Seven sprint and eight distance male specialists performed one maximum 400 m swim through a 6.75 m3 calibrated space recorded by six gen-locked cameras. The following variables were calculated: average swim velocity, stroke length, stroke frequency, upper limb and foot displacement, elbow angle, the shoulder and hip roll angle, duration of the stroke phases and time corresponding to particular events within the stroke cycle relative to hand entry. Differences between the groups were assessed by an independent t-test and effect size (d) calculations for each variable. The groups only differed significantly with respect to the average swim velocity, with the distance swimmers maintaining a greater velocity throughout the 400 m. However, effect sizes were moderate for elbow angle range during the pull phase (d = 0.78) and the total hip roll magnitude (d = 0.76). There was little evidence to suggest that sprint and distance swimmers using a six beat kick pattern differ in technique when swimming at a distance pace and therefore coaches should not encourage the development of different techniques between these groups. 相似文献
16.
Senda Sammoud Alan Michael Nevill Yassine Negra Raja Bouguezzi Chaabene Helmi Younés Hachana 《Journal of sports sciences》2019,37(10):1162-1167
The purpose of this study was to estimate the optimal body size, limb-segment length, girth or breadth ratios for 100-m backstroke mean speed performance in young swimmers. Sixty-three young swimmers (boys [n = 30; age: 13.98 ± 0.58 years]; girls [n = 33; age: 13.02 ± 1.20 years]) participated in this study. To identify the optimal body size and body composition components associated with 100-m backstroke speed performance, we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 100-m backstroke mean speed performance and the different somatic measurements estimated that biological age, sitting height, leg length for the lower-limbs, and two girths (forearm and arm relaxed girth) are the key predictors. Stature and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. In fact, it is only by adopting multiplicative allometric models that the abovementioned ratios could have been derived. These findings highlighted the importance of considering somatic characteristics of young backstroke swimmers and can help swimming coaches to classify their swimmers and enable them to suggest what might be the swimmers’ most appropriate stroke (talent identification). 相似文献
17.
Intensity of exercise recovery, blood lactate disappearance, and subsequent swimming performance 总被引：1，自引：0，他引：1
Greenwood JD Moses GE Bernardino FM Gaesser GA Weltman A 《Journal of sports sciences》2008,26(1):29-34
The aim of this study was to examine the effects of active versus passive recovery on blood lactate disappearance and subsequent maximal performance in competitive swimmers. Fourteen male swimmers from the University of Virginia swim team (mean age 20.3 years, s= 4.1; stature 1.85 m, s= 2.2; body mass 81.1 kg, s= 5.6) completed a lactate profiling session during which the speed at the lactate threshold (V(LT)), the speed at 50% of the lactate threshold (V(LT.5)), and the speed at 150% of the lactate threshold (V(LT1.5)) were determined. Participants also completed four randomly assigned experimental sessions that consisted of a 200-yard maximal-effort swim followed by 10 min of recovery (passive, V(LT.5), V(LT), V(LT1.5)) and a subsequent 200-yard maximal effort swim. All active recovery sessions resulted in greater lactate disappearance than passive recovery (P < 0.0001 for all comparisons), with the greatest lactate disappearance associated with recovery at V(LT) (P= 0.006 and 0.007 vs. V(LT.5) and V(LT1.5) respectively) [blood lactate disappearance was 2.1 mmol l(-1) (s= 2.0), 6.0 mmol l(-1) (s=2.6), 8.5 mmol l(-1) (s= 1.8), and 6.1 mmol l(-1) (s= 2.5) for passive, V(LT.5), V(LT), and V(LT1.5) respectively]. Active recovery at VLT and V(LT1.5) resulted in faster performance on time trial 2 than passive recovery (P=0.005 and 0.03 respectively); however, only active recovery at V(LT) resulted in improved performance on time trial 2 (TT2) relative to time trial 1 (TT1) [TT2- TT1: passive +1.32 s (s= 0.64), V(LT.5) +1.01 s (s= 0.53), V(LT) -1.67 s (s= 0.26), V(LT1.5) -0.07 s (s = 0.51); P < 0.0001 for V(LT)). In conclusion, active recovery at the speed associated with the lactate threshold resulted in the greatest lactate disappearance and in improved subsequent performance in all 14 swimmers. Our results suggest that coaches should consider incorporating recovery at the speed at the lactate threshold during competition and perhaps during hard training sessions. 相似文献
18.
Blanksby B Skender S Elliott B McElroy K Landers G 《Sports biomechanics / International Society of Biomechanics in Sports》2004,3(1):1-14
Kinetic (3-D force plate), kinematic (videography) and temporal characteristics of backstroke turns by 20 male and 16 female swimmers were recorded to identify and describe key elements of backstroke turning performance. Data were recorded during a 50 m maximum effort swim in a 25 metre pool. A Pearson product moment correlation matrix revealed that the 5 m RTT was significantly correlated with anthropometric measures of height, mass, trochanteric height and age; kinetic measures of horizontal impulse and peak force; and kinematic measures of wall contact time and peak velocity. The stepwise multiple regression equation to predict 5 m RTT was: 19.6-0.75 trochanteric height-1.8 wall exit velocity-0.03 peak vertical force. Four key factors were identified from a principle components factor analysis--anthropometry and force, post-turn velocity, force preparation and rotational skills. Implications from the findings were that age-group backstrokers should 'hit the wall hard' with relatively extended legs to reduce swim distance and push-off deceleration; use minimal wall contact time, and maximise forces to develop high horizontal velocities in a streamlined position. 相似文献
19.
应用CF-Ⅳ型心血管功能检测仪,对24名优秀的少儿男女游泳运动员(男12名、女12名)以及12名普通男少儿,在安静及100W功率自行车运动后即刻心血管功能指标进行测试。结果发现:安静及100W负荷时,运动员心率(HR)都低于非运动员(P<0.05),而每搏输出量(SV)以及100W负荷时的收缩压(SBP)却高于非运动员(P<0.05);心输出量(CO)的相对值及血乳酸(BLA)在100W负荷时运动员的上升幅度较小(P<0.05及P<0.01)。男女运动员相比,心血管功能各指标间无显著性差异。结果显示了少儿游泳运动员心血管功能的提高以及机体供能的节省化。 相似文献
20.
Patrycja Lipińska Sian V. Allen Will G. Hopkins 《European Journal of Sport Science》2016,16(3):287-292
Pacing offers a potential avenue for enhancement of endurance performance. We report here a novel method for characterizing pacing in 800-m freestyle swimming. Websites provided 50-m lap and race times for 192 swims of 20 elite female swimmers between 2000 and 2013. Pacing for each swim was characterized with five parameters derived from a linear model: linear and quadratic coefficients for effect of lap number, reductions from predicted time for first and last laps, and lap-time variability (standard error of the estimate). Race-to-race consistency of the parameters was expressed as intraclass correlation coefficients (ICCs). The average swim was a shallow negative quadratic with slowest time in the eleventh lap. First and last laps were faster by 6.4% and 3.6%, and lap-time variability was ±0.64%. Consistency between swimmers ranged from low-moderate for the linear and quadratic parameters (ICC = 0.29 and 0.36) to high for the last-lap parameter (ICC = 0.62), while consistency for race time was very high (ICC = 0.80). Only ~15% of swimmers had enough swims (~15 or more) to provide reasonable evidence of optimum parameter values in plots of race time vs. each parameter. The modest consistency of most of the pacing parameters and lack of relationships between parameters and performance suggest that swimmers usually compensated for changes in one parameter with changes in another. In conclusion, pacing in 800-m elite female swimmers can be characterized with five parameters, but identifying an optimal pacing profile is generally impractical. 相似文献