Background: Practice of physical activity and sport is an ideal medium for obtain benefits biopsycho- socials health of young people. The aim of the current study is to know the reasons for practicing physical activity and sport in a representative sample of Spanish adolescents. Methods: A descriptive cross-sectional study was implemented and the survey about behaviours, attitudes and values related to physical activity and sport practice, which was developed in the AVENA study was used. The sample size was 2859 Spanish students from public and private secondary schools in 5 Spanish cities: Granada, Madrid, Murcia, Santander and Zaragoza. Results: The amusement, doing exercise, being with friends and the pleasure of this practice are, in this order, the main reasons for practicing physical activity and sport in their free time. Gender and age modify significantly the reasons for practicing physical activity and sports. Conclusions: The knowledge of the reason of practicing could allow to develop effective and longterm successful intervention programmes for adopting healthy lifestyles in the currently young people.Peer Reviewe
