The present study examined the relationship between achievement and social goals, and explored how both types of goals can affect secondary school students' persistence/effort in Physical Education classes, as well as their intention to participate in sport activities after finishing secondary school. A sample of 350 students (aged 15-17) from two high schools in Asturias participated in the study. Multiple regression analysis showed: a) persistence/effort in physical education classes was better explained by social responsibility goals, followed by mastery-approach goals and mastery-avoidance goals; b) achievement goals are the only predictors of young people's intention of practicing sport in the future. Differences were found in these results according to gender and course. These findings help us better understand the processes involved in Physical Education. Finally, implications to improve classes and to achieve young people's more active and higher level of implication in sports are discussed.