The natural environment has some characteristics that make it different and that allow the development of the participants at a physical, intellectual and emotional level. This environment used as a nature classroom, together with an adequate planning and organization of the activities, can contribute to the integral development of people. The aim of this study was to analyse the development of personal and social competences after a practical training experience in nature. Fifty-nine students of Physical Activity and Sport Sciences took part in this study. A questionnaire was administered in four temporal moments: before the theoretical sessions (pre-theory), after the conventional classroom teaching period (post-theory) and before and after a practical experience in nature (pre and post-nat). The descriptive statistics (mean +/- standard deviation) obtained in each one of the variables in the classroom were in interpersonal relationships 6.07 +/- 1.88 in pre and 6.63 +/- 1.71 in post, in autonomy 5.47 +/- 2.64 in pre and 6.36 +/- 2.16 in post, in self-confidence 4.69 +/- 2.14 in pre and 5.61 +/- 1.87 in post and in peer confidence 7.08 +/- 2.3 in pre and 7.2 +/- 2.02 in post. In natural environment in interpersonal relationships 6.63 +/- 1.71 in pre and 7.63 +/- 1.26 in post, in autonomy 6.36 +/- 2.16 in pre and 7.42 +/- 1.71 in post, in self-confidence 5.61 +/- 1.87 in the pre and 7.12 +/- 1.65 in post and in confidence in partners 7.2 +/- 2.02 in pre and 7.9 +/- 1.74 in post. Results obtained show significant improvements between pre and post, both in classroom sessions and in sessions in natural environment (P<0.05), except for confidence in peers that only improved significantly in post-nat. In addition, the size of the effect produced in classroom teaching period was small to moderate (0.06 to 0.49), while in practical experience in nature they were moderate and large (0.40 to 0.92) indicating a greater influence on the variables analysed.
