Abstract

The aim of the study was to quantify and assess the quality of the Physical Education (PE) lesson time spent by students in MVPA during 45 and 90 min classes. Data were collected through heart rate (HR) monitoring and SOFIT. The HR of 4 students from 6 teachers was assessed during 6 lessons (3 of 45 min and 3 of 90 min). PA levels of those students, as well as the lesson contexts in which they occurred, and teacher behaviours, were also observed and coded throughout each lesson, using SOFIT. A cluster analysis was made in reference to the students, establishing an individual comparison of different classes. Afterwards, an analysis was made in relation to the teachers. The average HR was 134±19 bpm for 45 and 131±9 bpm for 90 min classes. Teachers dedicated 60% and 57% of class time in MVPA, respectively to 45 and to 90 min lessons. In 45 min class lessons, 17% of the time was dedicated to promoting fitness and 32% to games. These percentages are superior to those of the 90 min class – 15% and 28%, respectively. As for PA intensity, despite the fact that there were no significant differences between the 45 and 90 min class, during 45 min there is a tendency for student HR to exceed 140 bpm for a longer time period. The results of the cluster analysis showed that games are the activities that characterise classes with moderate to vigorous intensity. A HR between 140 and 60 bpm is correlated with the time dedicated to fitness (r=0.64). No differences were found between the 45 and 90 min class periods, suggesting that from a pedagogical viewpoint, both options are adequate. Through SOFIT it was possible to verify that the activities with vigorous intensity happen in the periods in which the teacher had that intention, namely in the periods of fitness exercises and games. Thus, as for all teaching activities, the intensity of classes requires planning by PE teachers.