Key somatic variables in young backstroke swimmers

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)

Lower quarter Y balance test: reliability and relation to anthropometric parameters

This study aimed to analyze the Lower Quarter Y Balance Test (Y-BT) reliability in prepubescent male soccer players, as well as the relation between this dynamic balance test performance and some anthropometric parameter

Key anthropometric variables associated with front-crawl swimming performance in youth swimmers: an allometric approach

This is an accepted manuscript of an article published by Lippincott, Williams & Wilkins/National Strength and Conditioning Association in Journal of Strength and Conditioning Research on 07/02/2020, available online: 10.1519/JSC.0000000000003491 The accepted version of the publication may differ from the final published version.Sammoud, S, Negra, Y, Chaabene, H, Bouguezzi, R, Attia, A, Granacher, U, Younes, H, and Nevill, AM. Key anthropometric variables associated with front-crawl swimming performance in youth swimmers: an allometric approach. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to establish key anthropometric characteristics (e.g., optimal body height, limb-segment length, and girth/breadth ratios) related to 100-m front-crawl performance in young swimmers. In total, 74 swimmers (boys [n = 41; age: 18.1 ± 3.5 years]; girls [n = 33; age: 15.9 ± 3.1 years]) participated in this study. We adopted a multiplicative allometric log-linear regression model to identify key anthropometric characteristics associated with 100-m front-crawl swimming performance. The main outcomes indicated that length ratio = ([height/leg length]), foot length and ankle girth, biacromial breadth, and % of body fat were associated with 100-m front-crawl mean swimming speed performance. These findings highlight the importance of assessing anthropometric characteristics in young front-crawl swimmers for talent identification and development.Published versio

Reliability and construct validity of the karate-specific aerobic test

Chaabene, H, Hachana, Y, Franchini, E, Mkaouer, B, Montassar, M, and Chamari, K. Reliability and construct validity of the karate-specific aerobic test. J Strength Cond Res 26(12): 3454-3460, 2012-The aim of this study was to examine absolute and relative reliabilities and external responsiveness of the Karate-specific aerobic test (KSAT). This study comprised 43 male karatekas, 19 of them participated in the first study to establish test-retest reliability and 40, selected on the bases of their karate experience and level of practice, participated in the second study to identify external responsiveness of the KSAT. The latter group was divided into 2 categories: national-level group (G(n)) and regional-level group (Gr). Analysis showed excellent test-retest reliability of time to exhaustion (TE), with intraclass correlation coefficient ICC(3,1) >0.90, standard error of measurement (SEM) <5%: (3.2%) and mean difference (bias) +/- the 95% limits of agreement: -9.5 +/- 78.8 seconds. There was a significant difference between test-retest session in peak lactate concentration (Peak [La]) (9.12 +/- 2.59 vs. 8.05 +/- 2.67 mmol.L-1; p < 0.05) but not in peak heart rate (HRpeak) and rating of perceived exertion (RPE) (196 +/- 9 vs. 194 +/- 9 b.min(-1) and 7.6 +/- 0.93 vs. 7.8 +/- 1.15; p > 0.05), respectively. National-level karate athletes (1,032 +/- 101 seconds) were better than regional level (841 +/- 134 seconds) on TE performance during KSAT (p < 0.001). Thus, KSAT provided good external responsiveness. The area under the receiver operator characteristics curve was >0.70 (0.86; confidence interval 95%: 0.72-0.95). Significant difference was detected in Peak [La] between national- (6.09 +/- 1.78 mmol.L-1) and regional-level (8.48 +/- 2.63 mmol.L-1) groups, but not in HRpeak (194 +/- 8 vs. 195 +/- 8 b.min(-1)) and RPE (7.57 +/- 1.15 vs. 7.42 +/- 1.1), respectively. The result of this study indicates that KSAT provides excellent absolute and relative reliabilities. The KSAT can effectively distinguish karate athletes of different competitive levels. Thus, the KSAT may be suitable for field assessment of aerobic fitness of karate practitioners.Ministere de l'Enseignement Superieur et de la recherche Scientifique,'' Tunisia This study was supported by the Ministere de l'Enseignement Superieur et de la recherche Scientifique,'' Tunisia. The authors are grateful to all the participants for their enthusiasm and commitment to the completion of this study.Ministere de lEnseignement Superieur et de la recherche Scientifique, Tunisia This study was supported by the Ministere de lEnseignement Superieur et de la recherche Scientifique, Tunisia. The authors are grateful to all the participants for their enthusiasm and commitment to the completion of this study

Пасха

Выпякалі ўсё, што можна было, што ў нашых сілах было. І яічкі ўсяка красілі. Сабіраліся мужчыны маладыя і качалі яйцы. Адзін пакаціў яйко′, а другі – за ім, і нада, каб папала. І біліся яйцамі. Чыё яйко пабітае, той прайграў і аддаець яг

Validity and reliability of new agility test among elite and subelite under 14-soccer players

Background: Agility is a determinant component in soccer performance. This study aimed to evaluate the reliability and sensitivity of a "Modified Illinois change of direction test" (MICODT) in ninety-five U-14 soccer players. Methods: A total of 95 U-14 soccer players (mean ± SD: age: 13.61±1.04 years; body mass: 30.52±4.54 kg; height: 1.57±0.1 m) from a professional and semi-professional soccer academy, participated to this study. Sixty of them took part in reliability analysis and thirty-two in sensitivity analysis. Results: The intraclass correlation coefficient (ICC) that aims to assess relative reliability of the MICODT was of 0.99, and its standard error of measurement (SEM) for absolute reliability wa

Reliability and validity of a 20-s alternative to the wingate anaerobic test in team sport male athletes.

The intent of this study was to evaluate relative and absolute reliability of the 20-s anaerobic test (WAnT20) versus the WAnT30 and to verify how far the various indices of the 30-s Wingate anaerobic test (WAnT30) could be predicted from the WAnT20 data in male athletes. The participants were Exercise Science majors (age: 21.5±1.6 yrs, stature: 0.183±0.08 m, body mass: 81.2±10.9 kg) who participated regularly in team sports. In Phase I, 41 participants performed duplicate WAnT20 and WAnT30 tests to assess reliability. In Phase II, 31 participants performed one trial each of the WAnT20 and WAnT30 to determine the ability of the WAnT20 to predict components of the WAnT30. In Phase III, 31 participants were used to cross-validate the prediction equations developed in Phase II. Respective intra-class correlation coefficients (ICC) for peak power output (PPO) (ICC = 0.98 and 0.95) and mean power output (MPO) (ICC 0.98 and 0.90) did not differ significantly between WAnT20 and WAnT30. ICCs for minimal power output (POmin) and fatigue index (FI) were poor for both tests (range 0.53 to 0.76). Standard errors of the means (SEM) for PPO and MPO were less than their smallest worthwhile changes (SWC) in both tests; however, POmin and FI values were "marginal," with SEM values greater than their respective SWCs for both tests values. Stepwise regression analysis showed that MPO had the highest coefficient of predictability (R = 0.97), with POmin and FI considerable lower (R = 0.71 and 0.41 respectively). Cross-validation showed insignificant bias with limits of agreement of 0.99±1.04, 6.5±92.7 W, and 1.6±9.8% between measured and predicted MPO, POmin, and FI, respectively. WAnT20 offers a reliable and valid test of leg anaerobic power in male athletes and could replace the classic WAnT30

Reliability of WAnT₂₀ (values are means ±SD).

<p><b><i>PPO</i></b>: Peak Power Output; <b><i>MPO</i></b>: Mean Power Output; <b><i>PO_min</i></b>: Minimal Power Output;<b><i>FI</i></b>: Fatigue Index;</p>§<p>:Accept normality; <b><i>dz</i></b>: Cohen'd; <b><i>Heter Coeff</i></b>: Heteroscedasticity coefficient; <b><i>ICC</i></b>: Intra Class Correlation Coefficient; <b><i>SWC</i></b>: Smallest Worth While Change; <b><i>SEM</i></b>: Standard Error of Measurement.</p><p>Reliability of WAnT₂₀ (values are means ±SD).</p

Regression equations to estimate WAnT₃₀ indices from first 20-s values of the same test.

<p>PPO: Peak Power Output; MPO_WAnT30: Mean Power Output of the WAnT₃₀; PO_{min WAnT30}: Minimal Power Output of the WAnT₃₀; FI_WAnT30: Fatigue Index of the WAnT₃₀; P₅: Power at the 5^th s; P₁₅: power at the 15^th s; P₂₀: Power at the 20^th s.</p><p>Regression equations to estimate WAnT₃₀ indices from first 20-s values of the same test.</p