The aim of this study was to determine statistically significant positive effect that regular classes of physical education with the simultaneous additional sport activities have on 11-year old pupils (±6 months). The sample of 100 subjects was divided into two subsamples. The sample of 50 subjects consisted of pupils who only had regular classes of phusical education at school. The second subsample of 50 subjects consisted of pupils who, apart from the regular physical education classes at school also had the experimental programme of training for non-swimmer, 24 hours total (twice a week, for 45 minutes). The evaluate the morphological characteristics, a seto of five variables was applied. The obtained results indicate a statistically significant difference between the control and the experimental group in the following variables: the body mass index with the level of p =.003, and the body fat with the level of p =.043. According to the results, swimming classes can be an efficient means for reducing the fat level in school children. This kind of research can be a starting point for further research focused on various water activities, which will include both sexes, a larger sample of subjects, a greater number of swimming classes, as well as to examine the differences between the pupils who take swimming lessons and their peers who are in the training process for swimmers.
