Predicting sports performance and identifying
talented athletes at early ages seems to
be a challenging task for practioners and
researchers. Based on this, the follow-up of
individual pathway to exper?se should be a
regular procedure among sports practioners.info:eu-repo/semantics/publishedVersio

Barbosa, Tiago M.

Costa, M.J.

Marinho, D.A.

Marques, M.C.

Morais, J.E.

Moreira, Marc

Silva, A.J.

English

Morais, J. E.

Marques, Mário C.

Biblioteca Digital do IPB

Jorge E Morais1,6, Mário J Costa2,6, Marc Moreira3, Pedro Forte1, Mário C Marques4,6, António J Silva3,6, Daniel A Marinho4,6 and Tiago M Barbosa1,5,6  VARIABILITY IN YOUNG SWIMMER’ PERFORMANCE AND ITS DETERMINANT FACTORS: A TWO-YEAR FOLLOW-UP  Havriluk R. X Int Symposium of Biomech and Med in Swimming, 2006, 218-220.  Kolmogorov S and Duplisheva O. J Biomech, 1992, 25, 311-318.  Lä: E, et al. Percept Mot Skills, 2009, 108, 297-307.  Marinho DA, et al. J Sports Sci Med, 2010, 9, 71-78.  Morais  JE, et al. Pediatric Exerc Sci, 2012, 24, 649-664.  Philips E, et al. Sports Med, 2010, 40, 271-283.  Silva AF , et al. J Sports Sci Med, 2013, 12, 623-629.  Tella V, et al. XX Int Symposium on Biome-chin Sports, 2002, 64-67.  Zamparo P. Eur J Appl Physiol, 97, 52-58. 1Polytechnic Ins?tute of Bragança, Bragança, Portugal 2Polytechnic Ins?tute of Guarda, Guarda, Portugal 3University of Trás-os-Montes and Alto Douro, Vila Real, Portugal 4University of Beira Interior, Covilhã, Portugal 5Nanyang Technological University, Singapore 6Research Center in Sports, Health and human Development, Vila Real, Performance The official short course 100-m freestyle race (i.e. 25-m length swimming pool) was chosen as a performance measure.   Anthropometrics For all measurements swimmers were asked to wear only a tex?le swimsuit and a cap. Body surface areas (in cm2; hand surface ar-ea - HSA; foot surface area - FSA; trunk transverse surface area - TTSA) were meas-ured with digital photogrammetry (Morais et al., 2012). Body mass (BM, in kg), height (H, in cm), arm span (AS, in cm)  and chest perimeter (CP, in cm) were also measured.  Hydrodynamics Velocity Perturba?on Method was used to es?mate the ac?ve drag (Da, in N) and the coefficient of ac?ve drag (CDa, adimensional) (Kolmogorov and Duplisheva, 1992). Swim-mers performed two maximal trials of 25-m at front crawl with push-off start (one trial with and other without carrying on the per-turba?on device). Two expert evaluators with stopwatches measured the trials be-tween the 11th and 24th meters.   Kinema?cs and efficiency Both kinema?cs and efficiency were as-sessed during the same trials. Swimmers in-dividually performed three maximal free-style swim trials of 25-m with push-off start.   A speedo-meter’s (Swim speedo-meter, Swimsportec, Hildesheim, Germany) cable was a:ached to the swimmers’ hip.  Swimming velocity (v, in m·s-1) was comput-ed in the middle 15-m as: v=d/t. Stroke fre-quency (SF, in Hz) with a chrono-frequency counter. Stroke length (SL, in m) as: SL=v/SF. Speed fluctua?on (dv, adimensional) was calculated as: dv=cv=standard devia?on/mean. Stroke index (SI, in m2·s-1) as: SI=v*SL and  propelling efficiency (ηp, in %) as  Zam-paro et al. (2006).  It can be concluded that young swimmers display a meaningful improvement in perfor-mance and its determinant factors.   The changes rate is higher in boys than girls and are strongly related to growth and train-ing. Average varia?ons of the pooled sample did not express the individual and unique changes of each swimmer.   Therefore, prac??oners should designs cus-tomized training plans for each swimmer and academics put more focus on individual and dynamic analysis frameworks.    CONCLUSION   REFERENCES Predic?ng sports performance and iden?fy-ing talented athletes at early ages seems to be a challenging task for prac??oners and researchers. Based on this, the follow-up of individual pathway to exper?se should be a regular procedure among sports prac??on-ers.   Compe??ve swimming is a sport character-ized by a rela?onship between performance and mul?-disciplinary determinant factors. Several interac?ons between anthropomet-ric and kinema?c variables were reported in young swimmers, having a mediate or direct effect on hydrodynamics and performance (Morais et al., 2012).   Despite the nowadays state of the art, those previous interven?ons highlighted the uni-versal perspec?ve (i.e. mean data is report-ed and analyzed) instead of individual trends. Mean data express intra-individual changes that are shared by every subject. It is considered a non-variance between sub-jects, or if there is assumed as random error or noise in the dataset.   Hence, this universal perspec?ve focuses on the modal or norma?ve behavior. Recent re-views about the dynamics of talent develop-ment suggest that each athlete should be seen as a unique individual, where a com-plex and dynamical athlete-environment re-la?onship exists (Philips et al., 2010). There is a lack of training interven?ons and follow-ups in swimming that explored individual trends through a compe??ve season, name-ly in young swimmers.   The aim of this study was to: follow-up the overall, intra- and inter-individual stability of young talented swimmers’ performance and its determinant factors (anthropometrics, kinema?cs, hydrodynamics and efficiency) during two compe??ve seasons.   Thirty young swimmers (14 boys: 12.33 ± 0.65 years; 16 girls: 11.15 ± 0.55 years; both genders in Tanner stages 1-2 by self-evalua?on) were evaluated. They had at the beginning of the assessment 3.40 ± 0.56 years of training experience (training ses-sions per week: 5.09±0.87; average volume per session: 4.86±0.97 km).  INTRODUCTION Mean and individual stability Performance showed a significant improve-ment between first (M1) and last (M7) eval-ua?ons in both genders. Previous studies al-so pointed out a performance improvement for young swimmers during two consecu?ve years (Lä: et al., 2009). Similar trend was iden?fied in our par?cipants for the ?me-frame under study (Figure 2). Performance changes were related to very unique and in-dividual adapta?ons in each one of its de-terminant factors. Despite the meaningful improvement observed within and between seasons for both genders, boys improved more sharply their performance than girls (boys: -20.60%; girls: -12.81%). The delayed matura?on in boys may explain such phe-nomenon.   All anthropometric variables (i.e. lengths and body surfaces) increased significantly between M1 and M7 for both genders (Figure 3). Young swimmers, as any other children, experience physical changes as part of their normal biological develop-ment. Body mass, height, and therefore, limbs’ lengths and areas are some of the an-thropometric features that change with growth. Growth rate was higher in boys (5.81% to 21.43%) than girls (4.95% to 19.02%) for all anthropometric features. These data suggested that boys were in an accelerated development stage, while girls have eventually experienced such biological development before.   METHODS All kinema?c and efficiency variables (except the dv) increased between M1 and M7 (Figure 4). Kinema?cs and efficiency changed in boys (1.58% to 23.96% for) and girls (0.86% to 48.84%). Only v and SI (both genders) and SL (only girls) showed a signifi-cant increase (M1 vs M7). The improvement of swimming speed of young swimmers be-tween two major compe??ons was report-ed as being related to SL increases and SF decreases (Tella et al., 2002). This SL-SR rela-?onship is a result of growth (e.g. height, arm span, hands and feet dimensions). Therefore, growth plays a role in the young swimmers’ mechanics (Silva et al., 2013).   Regarding hydrodynamics, both Da and CDa increased between M1 and M7 in both gen-ders; however, only girls’ Da showed a sig-nificant increase (Figure 3). Unchanged hy-drodynamics was reported for eight weeks of training at the beginning of a season (Marinho et al., 2010). The main aim of this general period of prepara?on was to build-up aerobic capacity and aerobic power, en-hance swimming technique. However, one week of drill training with specific visual and kinaesthe?c feedbacks, was enough to de-crease CDa in pubescent swimmers (Havriluk, 2006). So, hydrodynamic enhancement is more related to technical ability than to en-erge?c build-up.  Figure 2.  Performance varia?on along the two seasons. (A) Xboys and Xgirls mean varia?ons; (B) boys individual varia?ons; (C) girls individual varia?ons; PERF – performance@100free; M – moment; * – significant differences between moments for both boys and girls (p≤0.05); # – significant differences between moment one (ini?al) and moment seven (final) for boys (p<0.001); β – significant differences between moment one (ini?al) and moment seven (final) for girls (p<0.001).  Figure 3. Anthropometric and hydrodynamic varia?on along the two seasons. (A) Xboys and Xgirls mean varia?ons; (B) boys individual varia?ons; (C) girls individual varia?ons; BM – body mass; AS – arm span; H – height; CP – chest perimeter; TTSA – trunk transverse surface area; HSA – hand surface area; FSA – foot surface area; Da – ac?ve drag; CDa – ac?ve drag coefficient; M – moment; * – significant differences be-tween moments for both boys and girls (p≤0.05); # – significant differences between moment one (ini?al) and moment seven (final) for boys (p<0.001); β – significant differences between moment one (ini?al) and moment seven (final) for girls (p<0.05). Figure 4 Kinema?c and energe?c varia?on along the two seasons. (A) Xboys and Xgirls mean varia?ons; (B) boys individual varia?ons; (C) girls individual varia?ons; SF – stroke frequency; SL – stroke length; v – swimming velocity; dv – speed fluctua?on; ηp – propelling efficiency; SI – stroke index; M – moment; * – significant differences between moments for both boys and girls (p≤0.05); # – significant differences be-tween moment one (ini?al) and moment seven (final) for boys (p<0.01); β – significant differences be-tween moment one (ini?al) and moment seven (final) for girls (p<0.05).    RESULTS AND DISCUSSION  RESULTS AND DISCUSSION  METHODS  ACKOWLEDGMENTS Jorge E. Morais would like to acknowledge to the Portuguese Science and Technology Founda?on (FCT) for the PhD grant (SFRH/BD/76287/2011).   RESULTS AND DISCUSSION Inter-individual stability based on Cohen’s Kappa quan?fies the par?al posi?on of a swimmer against remaining contenders. A higher stability indicates that there are few-er changes in the par?al posi?on of the sub-jects throughout the ?me-frame under anal-ysis. There was a moderate stability for per-formance and anthropometrics (boys and girls). However, kinema?cs, efficiency and also hydrodynamics showed a low-moderate and a low stability for boys and girls, respec-?vely, hence a high variability. These find-ings suggest that growth and biological de-velopment are strongly associated with per-formance. In such early ages, swimmers that are in more advances stages of biological de-velopment take the lead and rank on the top. Nevertheless, not only growth and bio-logical development can determine perfor-mance. Hydrodynamics (e.g. Da), efficiency (e.g. SI) and kinema?cs (e.g. SF for boys and v for girls) should also be highlighted as ma-jor players since presented as well high cor-rela?ons.   Figure 1.  Swim speedo-meter. 

Variability in young swimmer’ performance and its determinant factors: a two-year follow-up

https://bibliotecadigital.ipb.pt/bitstream/10198/17873/1/Wrocklaw%202014.pdf

Variability in young swimmer’ performance and its determinant factors: a two-year follow-up

Abstract

Similar works

Full text

Available Versions

Biblioteca Digital do IPB