"However, the rules need to be unified and, "for that purpose it would be very useful to know the extent to which the players experience exertion", says Fuentes. With this aim in mind, she studied the players participating in the last round of the Gipuzkoa Youth Championships; a total of 150 youngsters, 67 boys and 83 girls. Fuentes believes it is important to look after the children in these early stages, because the experiences they go through could have a tremendous influence on the way they may subsequently develop in the sport. So to measure the perception of exertion that these players have, she has used the Eston-Parffit pictorial scale, “because it is accessible, easy to use and effective, and because it has been adapted to children,” as Fuentes points out. She conducted her data gathering during the Last Round of the Gipuzkoa Championships; over three consecutive weekends in May, 2010, in the girls’ and boys’ quarter-finals, semi-finals and finals. At the end of each half of the matches the mini-basketball players had to indicate how tired they felt (RPE-Rated Perceived Exertion). That way Fuentes obtained the RPEin terms of time played as well as the average RPE per match. According to what the players indicated, on average what they feel is between moderate exertion and great exertion, and there was no obvious difference between girls and boys. However, there is a difference in the perceived exertion depending on whether the match had been won or lost: the RPE was greater in the groups that lost a quarter or a match. In addition, the trainers were also asked to provide an RPE on each player at the end of each match. Their perception concurred with what the children indicated; Fuentes felt that this was “very positive”. “In fact the trainers are asking the players to make an effort, and so it is of great interest to them to know how tired the players are, because they don't have any other means for this, like pulsemeters or anything like that.” In addition, the results of the thesis clearly showed that training is the factor which has the greatest influence on exertion. In other words, the more the players train, the less tired they feel.So knowing the perception of exertion is useful in order to plan the duration of the training and the number of training sessions per week and per year. The other factors that influence the perception of exertion are how long they have been playing mini-basketball and general sports habits. Without putting all this on one side, in Fuentes’ opinion, "what should be pointed out is that the research has shown that the Eston-Parfitt pictorial scale is totally valid and reliable for measuring the players’ exertion, both in the matches and in the training sessions, and that it can be used in any sport. "Finally, Fuentes believes her thesis could provide a starting point for conducting a study into other rules. Maite Fuentes-Azpiroz (Donostia-San Sebastian, 1960) has a degree in Teacher Training and Physical Education, and is the Dean of the Faculty of Physical Activity and Sports Sciences of the EHU/UPV.She wrote up her thesis under the supervision of three lecturers:SebastiánFeu-Molina, Assistant Dean of the Academic Affairs Directorate of the Faculty of Education of Extremadura; Julio Calleja-González, lecturer at the Faculty of Physical Activity and Sports Sciences of the EHU/UPV; and Concha Jiménez-Sánchez, lecturer at the Spanish Institute for Physical Education. This piece of research was made possible by funding from the Charter Provincial Council of Gipuzkoa and the Basketball Federation of Gipuzkoa.