[en] This doctoral thesis falls within the field of Physical Education and Sports Science, as part of an approach that could be defined as the study of training in basketball. Its principal objective is to better understand perceived exertion in 12 year-old Minibasketball players during competition. The sample selected are boys and girls who participated in the final phase of the Giipuzkoa 12 year-old championships. The instrument chosen to measure the afore-mentioned perceived exertion was the Eston-Parfitt pictorial scale given its validity, reliability and suitability for youngsters. The collection of data took place over the course of three consecutive weekends in May 2010 during the final stages of the Gipuzkoa Championships, consisting of the boys¿ and girls¿ quarter- finals, semi-finals and finals. Players of both sexes had to express their RPE at the end of each period of participation taking into account the specific rules of competition. In this way it was possible to obtain an RPE for periods of participation as well as an average RPE for the game as a whole. At the same time coaches were invited to give their RPE for their respective players at the end of the games.The results of the statistics analysed, indicate that the participants expressed an average RPEmedia = 4.41 ± 1.61, establishing average values for each period of between RPE = 4 and RPE = 5, with an expected variation of between 1.60 y 1.95. These correspond to an exertion between moderate and strong. There are no significant differences between the sexes. Significant differences were found however, depending on whether the match ended in victory or defeat (p < .01); higher RPE was noted among those teams that lost a quarter or a match.In posterior analysis, logical regression was applied with a view to establishing the association between variables and calculating the Odds Ratio, with a 95% rate of fiability. This produces results that indicate that 32% of the variation observed in the average RPE of a match occur as a result of the following variables: length of the training session, number of weekly and annual sessions, years playing Minibasketball and years doing sport.Finally, it was observed that the RPE expressed by the trainers coincided with the average RPE of the participants in the competition (rs = .347; p < .01), which indicates that this rate could be useful for those responsible for the design of training and preparation to meet the demands of competition.Key words: Minibasket, rate perceived exertion, competition.

[eu] Kirol eta Gorpuntz Hezkuntzaren Zientzien alorrean kokatuta dago Doktore-Tesi hau, saskibaloiaren inguruko formakuntza ikerketa-gai hartuta. Lehian ari direla, Minibasketeko alebin mailako jokalarien, neska zein mutilen, nekearen pertzepzioa (RPE) ezagutzea da tesi honen helburu nagusia.Laginerako aukeratutakoak Gipuzkoako Alebin txapelketaren azken fasean parte hartutako jokalariak dira: guztira 150, horietatik, 67 mutiko eta 83 neskato. Eston-Parffit izeneko eskala piktorikoa izan da (EP) nekea neurtzeko erabili den tresna, hura bitarteko baiotsu, fidagarri, ekolojiko eta gazteentzako egokia dela agerikoa baita. Gipuzkoako Txapelketako Amaiera Fasean egin zen datu bilketa; 2010eko maiatzeko hurrenez hurreneko hiru asteburutan, mutiko zein neskatoen finalaurden, finalaurreko eta finalak jokoan zirela. Minibasketeko jokalariek, partiduen zati bakoitzaren amaIeran, RPE-a adierazi behar zuten, beti ere lehiaketako araudia aintzat hartuta. Era honetan, jokatutako denboraren araberako RPE-a nola partiduko batez besteko RPE-a lortu ziren; honez gain, partiduak amaitutakoan, entrenatzaileei ere jokalarien RPE-a eskatu zitzaien.Analisi estatistikoen emaitzek diotenez, parte-hartzaileen batez besteko RPE-a =4.41 ± 1.61 araberakoa izan da, aldi bakoitzeko batez besteko balioen joera RPE=4 eta RPE=5 artean delarik, 1.60 eta 1.95 arteko desbideratze tipiko batez. Hartara, esfortzua neurritsu eta handia artekoari dagokio, neska eta mutilen artean alde nabarmenik izan ez delarik. Aldeak (p ¿ .01), ordea, garaipena eta porrotaren arabera nabarmendu dira, izan ere, RPE handiagoa agertu da laurdena edo partida galdu duten taldeetan.Geroko analisian erregresio lojistikoa egin zen, aldagaien arteko lotura eredu egiteko eta Odds Ratio -ak (OR) kalkulatzeko, %95eko fidagarritasunarekin. Ondorioa da partiduko batez besteko RPEa-ren aldagaien %32a, honako aldagaien araberakoa dela: entrenamenduaren iraupena, asteko eta urteko lan saio kopurua, Minisbasketean emandako urteak eta bizierari dagozkion kirol ohiturak.Azkenik ikusi da entrenatzaileek adierazitako RPE-a bat datorrela lehiaketako parte-hartzaileen batez besteko RPEarekin (rs = .347; p ¿ .01), horrek erakusten digu kirol teknikoek indize hori balia dezaketela entrenamenduetako lan zamak lehiaketaren eskaerei egokitzeko.