RELATIONSHIP BETWEEN FUNCTIONAL CAPACITY AND COMPETITIVE SUCCESSFULLNESS OF TENNIS PLAYERS COMPETING IN THE 12 TO 14 AGE CATEGORY

Cilj istraživanja jest utvrditi povezanost između pokazatelja funkcionalnih sposobnosti i natjecateljske uspješnosti tenisača i tenisačica u kategoriji natjecanja od 12-14 godina. Uzorak ispitanika čini 34 tenisača i 22 tenisačice u dobi od 12.3 do 14.9 godina koji se natječu u dobnoj kategoriji od 12 do 14 godina i rangirani su na rang listi Hrvatskog teniskog saveza. Povezanost između pokazatelja funkcionalnih sposobnosti i natjecateljske uspješnosti tenisača-ica utvrđena je Pearsonovim korelacijskim koeficijentom, a prediktivna vrijednost mjerenih parametara za procjenu natjecateljske uspješnosti uporabom regresijske analize. Rezultati ukazuju da postoji slaba, ali statistički značajna povezanost između parametara za procjenu aerobnog kapaciteta i natjecateljske uspješnosti u dječaka i djevojčica u dobnoj kategoriji 12-14 godina (p<.05). Također, postoji slaba, ali statistički značajna povezanost i između dobi i parametra za procjenu anaerobnog kapaciteta, i natjecateljske uspješnosti u dječaka u dobnoj kategoriji 12-14 godina (p<.05).The aim of the study was to investigate the relationship between indicators of functional capacities and the competitive successfulness of tennis players in the age category from 12 to 14 years. The sample of examinees consisted of 34 male and 22 female players from 12.3 to 14.9 years of age, competing in the age category from 12 to 14 years, that are ranked on the rank list of the Croatian tennis association. The relationship between measured parameters and competitive successfulness was established by the Pearson\u27s correlation coefficient, and the predictive value of the parameters for estimating competitive successfulness by means of the regression analysis. The results showed a moderate, but statistically significant correlation between aerobic capacity parameters and competitive successfulness in boys and girls in the 12 to 14 age category (p<.05). In boys, there were also moderate, but statistically significant correlations between age, anaerobic capacity and competitive successfulness (p<.05)

RECOMMENDED AMOUNTS OF MACRONUTRIENTS BEFORE AND AFTER TENNIS MATCHES

Tennis is one of the most popular sports played year-round. It is estimated that almost 60 million people are included in some sort of tennis matches and competitions. A tennis match can last longer than five hours at the professional level, so in tennis, similar to other sports that may last for extended periods of time, nutrition is considered an extremely important factor for ensuring the necessary energy during matches, as well as for the recovery period after the mentioned activities. The purpose of this paper is to investigate the area of the required intake of carbohydrates, protein, and fat before and after matches, to identify the desirable values that would ensure the necessary energy and expedite the recovery of tennis players after a match. Considering that tennis players use both the aerobic and the anaerobic energy systems as they play, carbohydrates are considered to be the main source of energy before and after matches, while proteins are considered to be extremely important factors for recovery after the activities. Unlike the mentioned food ingredients, the intake of fat has not been explored to that extent, from the aspect of the necessary intake before and after a match, but the daily recommended intake of 1.0 do 1.5 g/kg is very well known. Research has shown that the recommended values for the intake of carbohydrates before a match are 6 g/kg to 12 g/kg and 8 to 10 g/kg after a match. The desirable intake of protein just before a match is 0.3 g/kg and the same amount after a match (within 2 hours after the activity). Literature search has shown that the intakes are not uniform and that they depend on numerous factors, like sex, age, body mass, time of the match, length of the match, temperature, surface, tennis balls, and similar

Utvrđivanje razlika u situacijskim parametrima efikasnosti teniske igre na grand slam turnirima

The aim was to ascertain whether any differences in the performance indicators could be discerned when the indicators of the matches played in the year 2010 were compared with the matches played in 2011 at each of the three greatest Grand Slam tournaments - Roland-Garros (R-G), Wimbledon and US Open. The sample of entities consisted of 1524 game statistics records of 127 men single matches played within the main draw of each of the three tournaments in each of the two observed years. The basic central and dispersive parameters were calculated, and independent samples t-test was used to establish differences between the explored years (significance level p<.05). The smallest number of differences were determined for the R-G tournament. Generally, at all the three tournaments speed deceleration of the 1st and 2nd serve was obvious in 2011, probably indicating the shift of players’ focus on serve features other than power used for the active entrance into points. The number of unforced errors increased at R-G in 2011, whereas on the fast, grass, courts of Wimbledon and hard courts of US Open it was decreased, as well as the number of winners. The findings suggest that tennis play styles on fast courts tend to safer play with lower risks in the starting and middle phases of a point, whereas on slow courts styles are characterized with a more aggressive play in the middle phase of a point.Cilj ovog istraživanja bio je utvrditi razlike u situacijskim parametrima natjecateljske učinkovitosti teniske igre između istih Grand Slam turnira odigranih u 2010. i 2011. godini. Istraživanje je obuhvatilo tri Grand Slam natjecanja: Roland Garros, Wimbledon i US Open. Uzorak entiteta činila je statistika igre 1524 gema iz 127 pojedinačnih susreta muškaraca odigranih u glavnom ždrijebu navedena tri turnira tijekom dvije promatrane godine. Izračunati su osnovni centralni i disperzivni parametri varijabli, a razlike u statističkim parametrima za procjenu efikasnosti teniske igre utvrđene su t-testom za nezavisne uzorke (na razini značajnosti od p<0,05). Najmanje razlike pojavile su se na Roland Garrosu. Općenito, na sva tri Grand Slam natjecanja uočeno je smanjenje brzine prvoga i drugoga servisa u 2011. godini, što najvjerojatnije upućuje na to da se u filozofiji pristupa igri igrači više „okreću“ drugim obilježjima servisa osim same snage izvođenja kako bi aktivno ušli u poen. Na Roland Garrosu se u 2011. godini povećao broj neprisiljenih pogrešaka, dok je na brzoj travnatoj podlozi Wimbledona i betonskoj podlozi US Opena uočeno statistički značajno smanjenje broja neprisiljenih pogrešaka i winnera. Dobiveni rezultati na svojevrstan način daju do znanja kako tenis na brzim podlogama ide u smjeru nešto sigurnije igre s manjim rizikom u početnom i središnjem dijelu poena, a tenis na sporim podlogama kreće se u smjeru agresivnije igre u središnjem dijelu poena

Utvrđivanje razlika u situacijskim parametrima efikasnosti teniske igre na grand slam turnirima

The aim was to ascertain whether any differences in the performance indicators could be discerned when the indicators of the matches played in the year 2010 were compared with the matches played in 2011 at each of the three greatest Grand Slam tournaments - Roland-Garros (R-G), Wimbledon and US Open. The sample of entities consisted of 1524 game statistics records of 127 men single matches played within the main draw of each of the three tournaments in each of the two observed years. The basic central and dispersive parameters were calculated, and independent samples t-test was used to establish differences between the explored years (significance level p<.05). The smallest number of differences were determined for the R-G tournament. Generally, at all the three tournaments speed deceleration of the 1st and 2nd serve was obvious in 2011, probably indicating the shift of players’ focus on serve features other than power used for the active entrance into points. The number of unforced errors increased at R-G in 2011, whereas on the fast, grass, courts of Wimbledon and hard courts of US Open it was decreased, as well as the number of winners. The findings suggest that tennis play styles on fast courts tend to safer play with lower risks in the starting and middle phases of a point, whereas on slow courts styles are characterized with a more aggressive play in the middle phase of a point.Cilj ovog istraživanja bio je utvrditi razlike u situacijskim parametrima natjecateljske učinkovitosti teniske igre između istih Grand Slam turnira odigranih u 2010. i 2011. godini. Istraživanje je obuhvatilo tri Grand Slam natjecanja: Roland Garros, Wimbledon i US Open. Uzorak entiteta činila je statistika igre 1524 gema iz 127 pojedinačnih susreta muškaraca odigranih u glavnom ždrijebu navedena tri turnira tijekom dvije promatrane godine. Izračunati su osnovni centralni i disperzivni parametri varijabli, a razlike u statističkim parametrima za procjenu efikasnosti teniske igre utvrđene su t-testom za nezavisne uzorke (na razini značajnosti od p<0,05). Najmanje razlike pojavile su se na Roland Garrosu. Općenito, na sva tri Grand Slam natjecanja uočeno je smanjenje brzine prvoga i drugoga servisa u 2011. godini, što najvjerojatnije upućuje na to da se u filozofiji pristupa igri igrači više „okreću“ drugim obilježjima servisa osim same snage izvođenja kako bi aktivno ušli u poen. Na Roland Garrosu se u 2011. godini povećao broj neprisiljenih pogrešaka, dok je na brzoj travnatoj podlozi Wimbledona i betonskoj podlozi US Opena uočeno statistički značajno smanjenje broja neprisiljenih pogrešaka i winnera. Dobiveni rezultati na svojevrstan način daju do znanja kako tenis na brzim podlogama ide u smjeru nešto sigurnije igre s manjim rizikom u početnom i središnjem dijelu poena, a tenis na sporim podlogama kreće se u smjeru agresivnije igre u središnjem dijelu poena

DIFFERENCES AMONG TENNIS PLAYERS AGED 12, 14 AND 16 YEARS IN CERTAIN MORPHOLOGICAL CHARACTERISTICS: A CROATIAN PROSPECTIVE

Primary objective of this research was to identify quantitative differences among tennis players aged 12, 14 and 16 with regards to the indicators of morphological characteristics. Sixty (60) tennis players ranked on the scale of the Croatian Tennis Association were analysed through differences in morphological characteristics which were identified by a standard laboratory diagnostic procedure in Sports-diagnostic Centre of the Faculty of Kinesiology at the University of Zagreb. Significant differences were reached in most of the monitored measures for the assessment of the morphological characteristics. These differences are particularly reflected in the variables for assessment of longitudinal dimensionality of the skeleton (ALVT, ALDRL and ALDNL), and in the variables for the assessment of body volume and mass (AVTT, AVONDEL and AVOPDL). A bit smaller differences were reached at the variables for the assessment of transversal dimensionality of the skeleton (ATSR and ATSZ). The level of the statistical significance was defined at p<0.05. The results of the research indicate that the phase of the intensive period of the pubertal growth spurt in which the examined participants currently are, results with significant changes of body proportions. The above-mentioned indicates the importance of a quality methodologically formed and governed approach in the conditioning preparation of the young tennis players directed towards the development of the required morphological characteristics. Through the conditioning, but also technical-tactical training, actions should be undertaken for the prompt establishment of the impaired coordination competences with regards to the accelerated growth and development

RELATIONSHIP BETWEEN FUNCTIONAL CAPACITY AND COMPETITIVE SUCCESSFULLNESS OF TENNIS PLAYERS COMPETING IN THE 12 TO 14 AGE CATEGORY

Cilj istraživanja jest utvrditi povezanost između pokazatelja funkcionalnih sposobnosti i natjecateljske uspješnosti tenisača i tenisačica u kategoriji natjecanja od 12-14 godina. Uzorak ispitanika čini 34 tenisača i 22 tenisačice u dobi od 12.3 do 14.9 godina koji se natječu u dobnoj kategoriji od 12 do 14 godina i rangirani su na rang listi Hrvatskog teniskog saveza. Povezanost između pokazatelja funkcionalnih sposobnosti i natjecateljske uspješnosti tenisača-ica utvrđena je Pearsonovim korelacijskim koeficijentom, a prediktivna vrijednost mjerenih parametara za procjenu natjecateljske uspješnosti uporabom regresijske analize. Rezultati ukazuju da postoji slaba, ali statistički značajna povezanost između parametara za procjenu aerobnog kapaciteta i natjecateljske uspješnosti u dječaka i djevojčica u dobnoj kategoriji 12-14 godina (p<.05). Također, postoji slaba, ali statistički značajna povezanost i između dobi i parametra za procjenu anaerobnog kapaciteta, i natjecateljske uspješnosti u dječaka u dobnoj kategoriji 12-14 godina (p<.05).The aim of the study was to investigate the relationship between indicators of functional capacities and the competitive successfulness of tennis players in the age category from 12 to 14 years. The sample of examinees consisted of 34 male and 22 female players from 12.3 to 14.9 years of age, competing in the age category from 12 to 14 years, that are ranked on the rank list of the Croatian tennis association. The relationship between measured parameters and competitive successfulness was established by the Pearson\u27s correlation coefficient, and the predictive value of the parameters for estimating competitive successfulness by means of the regression analysis. The results showed a moderate, but statistically significant correlation between aerobic capacity parameters and competitive successfulness in boys and girls in the 12 to 14 age category (p<.05). In boys, there were also moderate, but statistically significant correlations between age, anaerobic capacity and competitive successfulness (p<.05)

DIFFERENCES AMONG TENNIS PLAYERS AGED 12, 14 AND 16 YEARS IN CERTAIN MORPHOLOGICAL CHARACTERISTICS: A CROATIAN PROSPECTIVE

Primary objective of this research was to identify quantitative differences among tennis players aged 12, 14 and 16 with regards to the indicators of morphological characteristics. Sixty (60) tennis players ranked on the scale of the Croatian Tennis Association were analysed through differences in morphological characteristics which were identified by a standard laboratory diagnostic procedure in Sports-diagnostic Centre of the Faculty of Kinesiology at the University of Zagreb. Significant differences were reached in most of the monitored measures for the assessment of the morphological characteristics. These differences are particularly reflected in the variables for assessment of longitudinal dimensionality of the skeleton (ALVT, ALDRL and ALDNL), and in the variables for the assessment of body volume and mass (AVTT, AVONDEL and AVOPDL). A bit smaller differences were reached at the variables for the assessment of transversal dimensionality of the skeleton (ATSR and ATSZ). The level of the statistical significance was defined at p<0.05. The results of the research indicate that the phase of the intensive period of the pubertal growth spurt in which the examined participants currently are, results with significant changes of body proportions. The above-mentioned indicates the importance of a quality methodologically formed and governed approach in the conditioning preparation of the young tennis players directed towards the development of the required morphological characteristics. Through the conditioning, but also technical-tactical training, actions should be undertaken for the prompt establishment of the impaired coordination competences with regards to the accelerated growth and development

Morphological and physiological profile indicators of physical fitness in male tennis players aged 12, 14 and 16 years

The establishment of differences in certain morphological characteristics and aerobic energy supply ability among three age categories of Croatian male teenage tennis players was the aim of this cross-sectional study. The sample consisted of 60 players classified into three categories by age: U12 (n=20; 12.1±0.4 years), U14 (n=20; 14.0±0.6 years) and U16 (n=20; 15.9±0.4 years). Nine morphological body measures were taken: body height; body mass; skinfolds of the back, upper arm, chest, abdomen, thigh, lower leg and suprailiocristal. Also, six variables of cardiopulmonary function were obtained using spirometry and spiroergometry testing. Basic statistical parameters were calculated and ANOVA was applied using Tukey’s post-hoc method. Statistically significant differences were obtained in the variable maximum treadmill speed (p<.01) and maximum treadmill speed at the anaerobic threshold (p<.01). Aerobic levels of the Croatian U12, U14 and U16 tennis players were in line with the requirements of high-performance tennis. The results indicated that the conducted physical conditioning and tennis-specific training programmes had a positive effect on the development of aerobic energy capacity indicators in the examined young tennis players. However, due to the age of subjects, the effect of dynamic processes of growth and maturation on the obtained results in the aerobic capacity test cannot be overlooked

THE INFLUENCE OF FITNESS - MOTOR PREPAREDNESS ON THE QUALITY OF OFFICIATING IN BASKETBALL

S obzirom na izrazitu dinamičnost košarkaške igre za pretpostaviti je da kvalitetnija kondicijsko – motorička priprema sudaca omogućuje lakše praćenje kretnji igrača tijekom igre što u konačnici rezultira boljom kvalitetom suðenja. Cilj u ovom istraživanju bio je utvrditi utjecaj kondicijsko - motoričke pripremljenosti košarkaških sudaca na njihovu kvalitetu suðenja. Uzorak ispitanika sastojao se od 31 suca, prosječne dobi 33,35±5,17 godina koji su se nalazili na A listi sudaca I. Hrvatske košarkaške lige u natjecateljskoj sezoni 2008/2009., dok je uzorak varijabli bio sastavljen od testova za procjenu motoričkih i funkcionalnih sposobnosti te tri varijable pod nazivom Dob, Iskustvo i Kvaliteta suðenja. Obrada podataka izvršena je primjenom programskog paketa STATISTICA for Windows, ver. 8. Višestrukom (multiplom) regresijskom analizom pokušala se utvrditi zavisnost funkcionalnih i motoričkih sposobnosti (nezavisne varijable) i kvalitete suðenja na košarkaškim utakmicama (zavisna varijabla). Dobiveni rezultati regresijske analize pokazali su da nema statistički značajne povezanosti izmeðu kondicijsko - motoričke pripremljenosti (motoričkih i funkcionalnih sposobnosti) sudaca i njihove kvalitete suðenja, odnosno rezultati su potvrdili pretpostavku kojom iskusniji suci uz prijeko potrebno teorijsko znanje „oplemenjeno“ istančanim osjećajem za igru postižu bolje rezultate u suðenju uz preduvjet dobre kondicijsko - motoričke pripremljenosti.Considering the great dynamics of the game of basketball it can be assumed that better fitness – motor preparation of the referees allows better monitoring of the players during the game, which ultimately results in better quality of game officiating. The object of this research was to determine the influence of fitness – motor preparation of basketball referees on their officiating quality. The sample of respondents consisted of 31 referees, the avarrege age of 33,35±5,17, who were on the A referee list of the First Croatian Basketball League in the season 2008/2009., while the sample of variables consisted of tests for assessment of motor and functional abilities, and three variables by the name of Age, Experience and Qualitiy of officiating. Data processing was performed using the software package STATISTICA for Windows, ver. 8. Regression analysis was used to determine dependence of functional and motor abilities (independent variables) and quality of officiating basketball games (dependent variable). The results obtained by regression analysis showed that there is no statistically significant relation between fitness – motor preparation (motor and functional abilities) of the referees and their quality of game officiating, or in other words, the results confirmed the assumption by which more experienced referees, with the necessary theoretical knowledge enriched with aesthetic feeling for the game, achieve better results in officiating a game with the requirement of good fitness – motor preparation

A COMPARISON OF TENNIS PLAYERS\u27 LOADS ON TWO DIFFERENT COURT SURFACES

Cilj ovoga istraživanja je usporediti opterećenje tenisača s obzirom na igru na različitoj podlozi – beton i zemlja. U tu svrhu 20 tenisača seniorskog uzrasta, koji su bili rangirani na ATP ljestvici odnosno do 25 mjesta rang liste Hrvatskog teniskog saveza, odigrali su 20 susreta. Od ukupnog broja 10 susreta su igrali na zemljanoj podlozi, a 10 susreta na betonskoj podlozi uz uvjet da su isti parovi igrača odigrali susrete na obje podloge. Svaki susret je snimljen s dvije kamere radi dobivanja što pouzdanijih podataka vezanih uz osnovnu tenisku statistiku. Procjena fiziološkog opterećenja na teniskom terenu provedena je praćenjem frekvencije srca i koncentracije laktata. Zaključeno je kako je u ovom istraživanju kod istih parova igrača podloga utjecala na različitu distribuciju opterećenja koje je izazvalo značajno povećanje frekvencije srca i energetsku potrošnju tijekom igre na zemljanoj podlozi. Interesantno je da distribucija opterećenja i duže trajanje pojedinih dijelova igre (poena, gema) nije utjecalo na razliku u ukupnom broju odigranih poena po satu igre. Dakle po satu susreta na betonskoj podlozi se nije odigralo više poena, ali je loptica na zemljanoj podlozi duže bila u igri tijekom poena, gema i susreta. Poeni se po svojoj strukturi i zahtjevnosti razlikuju većim brojem udaraca, dužim i većim brojem izmjena u poenu i gemu, što tijekom sata igre dovodi do značajno veće energetske potrošnje na zemljanoj podlozi.The aim of this study was to compare tennis players’ physiological demands on different tennis surfaces: clay court and hard court. The study included twenty senior players aged 21.45±3.45, from ATP (from 400 ATP) to national level (to 25th place in Croatia’s national rankings). They played 20 matches, 10 on a clay court and 10 on a hard court. Same pairs of players played on both surfaces (hard court - clay court). All matches where recorded using two digital video cameras in order to obtain reliable match statistics data. The demands of tennis match play were assessed by monitoring heart rate and lactate level. Based on the results of the study, it was concluded that, for the same pairs of players, the type of court surface impacted physiological demands differently, thus yielding higher heart rates and higher energy expenditures during match play on the clay court. Interestingly, differences in energy demands on the clay court when certain parts of match play (point, games) lasted for longer periods of time did not produce significant differences in the number of points played out during a one-hour match period. Thus, in one hour of match play, more points were not achieved on the hard court, but the ball was in play for a significantly longer period of time during the points, games, and during the one-hour period of match play. The points differed in terms of structure and demands because, during the match play on the clay court, the players performed more strokes, and the duration of the rallies, points, and games was longer. These factors provide a primary explanation as to why energy expenditures wee higher on the clay court surface