Analysis of Certain Dimensions of Anthropological Status of Young Soccer Players According to Biological and Chronological Age, Playing Line and Situational Efficiency : Doctoral Thesis

Osnovni cilj istraživanja bio je utvrditi utjecaj biološke i kronološke dobi na uspješnost nogometaša i dimenzije antropološkog statusa te analizirati razlike između mladih nogometaša različitih igračkih linija i situacijske uspješnosti u antropometrijskim karakteristikama, motoričko – funkcionalnim sposobnostima, specifičnim nogometnim sposbostima te nogometnoj vještini. Uzorak ispitanika bilo je 177 mladih nogometaša prosječne dobi 14.09±0.87 godina. Prosječna biološka dob ispitanika bila je 14.09±1.11 godina te se bave nogometom 6.61±1.86 godina. Radi obrade i interpretacije podataka cjelokupan uzorak je podijeljen u tri sub-uzorka prema igračkoj liniji (obrana N=70, vezni N=66, napad N=41) te dva sub-uzorka prema uspješnosti (uspješniji N=84, manje uspješni N=93). Uzorak varijabli sačinjavalo je 26 testova koji su bili podijeljeni u 5 skupina: antropometrijske karakteristike, motoričko-funkcionalne sposobnosti, specifične motoričke sposobnosti s loptom, indeks nogometne vještine. Za utvrđivanje postavljenih ciljeva i ispitivanje hipoteza ovog rada korištene su sljedeće metode obrade podataka: utvrdili su se deskriptivni i distribucijski statistički parametri za sve varijable, metrijske karakteristike testova (Cronbach alfa - CA, Inter - item interkorelacija - IIC, Test - retest, Koeficijent varijabilnosti između čestica - CV). Temeljem utvrđivanja dobi maksimalno ubrzanog rasta u visinu (APHV) izračunata je varijabla prosječna vrijednost APHV svih ispitanika. Dobivanjem varijable individualno odstupanje od prosječne vrijednosti APHV-a, ista je zbrojena ili oduzeta od varijable kronološke dobi te je definirana varijabla indikator biološke dobi. U svrhu utvrđivanja utjecaja biološke i kronološke dobi na uspješnost te ostale varijable antropološkog statusa primijenjena je serija multiplih regresijskih analiza. Multivarijatnim testom utvrđivane su razlike između igračkih linija i igrača različite uspješnosti prema biološkoj i kronološkoj dobi. Upotrebom ANCOVA-e s kontroliranjem utjecaja kovarijata (biološke dobi) utvrđene su razlike u antropološkom statusu između igrača različitih igračkih linija te između igrača različite uspješnosti unutar pojedinih igračkih linija. Uspješniji nogometaši u odnosu na manje uspješne postigli su bolje rezultate u svih 11 varijabli za procjenu motoričko – funkcionalnog statusa pri čemu su razlike statistički značajne u 9 varijabli. U varijablama za procjenu eksplozivne snage tipa horizontalne i vertikalne skočnosti (MSV, MSD, MBM) bolje rezultate su imali uspješniji nogometaši. Uspješniji nogometaši bilježe i značajno bolje rezultate u testovima za procjenu brzine (T20m, T30m) te agilnosti (Slalom, Zig-Zag, 93639), također, u varijabli YoYo (promjenjivi test s odmorima nivo 1) dobivene su statistički značajne razlike između igrača različite uspješnosti. Potvrđen je značajan utjecaj biološke i kronološke dobi na promatrane dimenzije antropološkog statusa mladih nogometaša. Također, u ovom istraživanju uspješniji nogometaši bili su statistički značajno biološki i kronološki zreliji od manje uspješnih nogometaša. Prema frekvencijama rođenih igrača po pojedinim mjesecima, kvartalima i polugodini utvrđen je efekt relativne dobi (ERD) odnosno asimetrija u raspodjeli rezultata koji su više grupirani prema početku kalendarske godine. Prethodno navedeno potkrepljuje osjetljivost odabira igrača i selekcije koja uvelike ovisi o trenutnom stupnju psihičkog i fizičkog razvoja mladih nogometaša. Utvrđeno je kod kojih testova se razlikuju uspješniji od manje uspješnih igrača unutar linija nakon eliminiranja utjecaja biološke dobi: Unutar obrambene igračke linije uspješniji igrači su se statistički značajno razlikovali od manje uspješnih u: antropometrijskim karakteristikama (ASV) te motoričko – funkcionalnim sposobnostima (MBM, T5m, T10m). Kod obrambenih igrača različite uspješnosti nisu pronađene značajne razlike specifičnim motoričkim sposobnostima s loptom, indeksu nogometne vještine kao ni u brzini udarca dominantnom i nedominantnom nogom. Uspješniji vezni igrači postigli su značajno bolje rezultate u odnosu na manje uspješne vezne igrače u: motoričko – funkcionalnim sposobnostima (MSD, MBM, T20m, Slalom, 93639, YoYo), specifičnim motoričkim sposobnostima s loptom (T20m L, Slalom L, 93639 L), indeksu nogometne vještine (T20m INV) te brzini udarca (MBUD, MBUN). Za ovaj uzorak ispitanika upotrebom ANCOVE vezni igrači različite uspješnosti nisu se statistički razlikovali u antropometrijskim karakteristikama. Kod napadača uspješniji igrači bili su statistički značajno bolji od manje uspješnih u: motoričko – funkcionalnim sposobnostima (MSV, MBM, YoYo), specifičnim motoričkim sposobnostima s loptom (T20m L, Slalom L, Zig-Zag L), indeksu nogometne vještine (T20m INV) te brzini udarca (MBUN).The main objective of this study was to determine the influence of biological and chronological age on success of players and dimensions of anthropological status. Also, one of the goals was to analyse differences between young players of different playing lines and situational success in anthropometric characteristics, motor - functional capabilities, soccer specific field tests and soccer skill index. The pattern of respondents included 177 young players aged 14.09 ± 0.87 years. The average biological age was 14.9 ± 11.1 years and the soccer experience was 6.61 ± 1.86 years. For the processing and interpretation of the results, the entire sample was divided in three sub-samples according to playing line (N = 70 defenders, midfielders N = 66, N = 41 attackers) and in two sub-samples according to situation efficiency (84 more successful, 93 less successful). The sample of variables consisted of 26 tests, divided in 5 groups: anthropometric characteristics, motor-functional abilities, specific motor abilities with the ball, soccer skill index. In order to determine the objectives and testing hypotheses of this study, the following methods were used for data processing: descriptive and statistical distribution parameters for all variables, metric characteristics of tests (Cronbach alpha - CA, Inter - item intercorrelation – IIC, test – retest method (r), coefficient of variation CV). According to method of Mirwald et al. (2002), APHV (age at peak height velocity) was calculated for every respondent. Mean APHV was calculated for the whole group and deviation for the every respondent. By adding previously mentioned deviation to chronological age of every respondent the number that is obtained is called indicator of the biological age according to method of Milic 2014. Multiple regression analysis was used in order to determine the influence of biological and chronological age on the efficiency and other variables of the anthropological status. With multivariate test, differences between different playing lines and different situational efficiency according to biological and chronological age, were calculated. Using ANCOVA (with covariate – indicator of the biological age) the differences in the anthropological status between players of different playing lines and differences between players who play in the same line but with different level of efficiency were analysed. Successful soccer players compared to the less successful ones achieved better results in all 11 variables for estimation of motor - functional status in which the differences are statistically significant for nine variables. More successful soccer players achieved better results in variables assessing explosive strength of horizontal and vertical jumping ability (MSV, MSD, MBM). More successful soccer players achieved better records and performance in tests assessing speed (T20m, T30m), agility (Slalom, Zig-Zag, 93639) and in variable YOYO (intermittent recovery test level 1) than less successful players. Main findings of this research include: *Significant influence of biological and chronological age on the observed dimensions of anthropological status of young players. *More successful soccer players were statistically and significantly more mature biologically and chronologically than those less successful ones *Effect of relative age (ERD) has been determined according to frequencies of born players per months, quarters and half-year. *It has been established in which tests there are significant differences between more successful and less successful players within playing line after eliminating the influence of biological age: More successful defenders were significantly different then less successful defenders in athropometric characteristics (ASV), motor - functional abilities (MBM, T5M, T10M). No significant differences were found in specific skills with the ball, soccer skill index as well in the ball kicking variables (MBUD, MBUN). More successful midfielders achived better results in motor - functional abilities (MSD, MBM, T20m, Slalom, 93639, YoYo), specific motor skills with the ball (T20m L, Slalom L, 93639 L), soccer skill index, (T20m INV), ball kicking speed (MBUD, MBUN). There were no significant differences in athropometric characteristics between more and less efficient midfielders. Successful attackers were better in motor - functional abilities (MSV, MBM, YoYo), specific motor skills with the ball (T20m L, L Slalom, Zig-Zag L), soccer skill index (T20m INV) and ball kicking speed (MBUN) then less successful attackers

Relative age effect and second-tiers: No second chance for later-born players

<div><p>The main objective of this research was to determine the existence of relative age effect (RAE) in five European soccer leagues and their second-tier competitions. Even though RAE is a well-known phenomenon in professional sports environments it seems that the effect does not decline over the years. Moreover, additional information is required, especially when taking into account second-tier leagues. Birthdates from 1,332 first-tier domestic players from France, England, Spain, Germany and Italy and birthdates from 1,992 second-tier domestic players for the 2014/2015 season were taken for statistical analysis. In addition to standard statistical tests, the data were analyzed using econometric techniques for count data using Poisson and negative binomial regressions. The results obtained confirmed a biased distribution of birthdates in favor of players born earlier in the calendar year. For all of the five first-tier soccer leagues there was an unequal distribution of birthdates (France <i>χ</i>² = 40.976, <i>P</i><0.001; England <i>χ</i>² = 21.892, <i>P</i> = 0.025; Spain <i>χ</i>² = 24.690, <i>P</i> = 0.010; Germany <i>χ</i>² = 22.889, <i>P</i> = 0.018; Italy <i>χ</i>² = 28.583, <i>P</i> = 0.003). The results for second-tier leagues were similar (France <i>χ</i>² = 46.741, <i>P</i><0.001; England <i>χ</i>² = 27.301, <i>P</i> = 0.004; Spain <i>χ</i>² = 49.745, <i>P</i><0.001; Germany <i>χ</i>² = 30.633, <i>P</i> = 0.001; Italy <i>χ</i>² = 36.973, <i>P</i><0.001). Econometric techniques achieved similar results: estimated effect of month of birth, i.e., long-term RAE on players’ representativeness, is negative (statistically significant at the 1% level). On average, one month closer to the end of the year reduces the logs of expected counts of players by 6.9%. Assuming this effect as linear, being born in the month immediately before the cut-off date (i.e., December/August), reduces the logs of expected counts of players by approximately 75.9%. Further, I_D (index of discrimination, that is, the ratio between the expected counts of players born in the middle of the first and the twelfth month of the selection year) is 2.13 and 2.22 for the first- and second-tier, respectively. In other words, in the top five European first-tier and second-tier leagues, one should expect the number of players born in the first month of the calendar year to be twice the number of those born in the last month. The RAE in the second-tiers is the same as in the first-tiers, so it appears that there is no second chance for later born players. This reduces the chances to recover talented players discarded in youth simply because of lower maturity.</p></div

RAE on frequency of month of birth in the first- and second-tiers of the five most important European leagues.

<p>RAE on frequency of month of birth in the first- and second-tiers of the five most important European leagues.</p

Soccer players’ birth dates monthly distributions for first- and second-tiers of the top five European leagues.

<p>Soccer players’ birth dates monthly distributions for first- and second-tiers of the top five European leagues.</p

Counts and <i>χ</i>² test of first- and second-tier players for the overall sample and for each country separately.

<p>Counts and <i>χ</i>² test of first- and second-tier players for the overall sample and for each country separately.</p

Predicted number of players per month for first- and second-tiers separately.

<p>Predicted number of players per month for first- and second-tiers separately.</p

Cognitive and Motivational Monitoring during Enriched Sport Activities in a Sample of Children Living in Europe. The Esa Program

Enriched Sport Activities (ESA) Program is an Evidence-based Practice Exercise Program cofounded by the Erasmus + Programme of the European Union (Key action: Sport-579661-EPP-1-2016-2-IT-SPO-SCP) [...