Physical inactivity is one of the leading health risk behaviors related to the global epidemic of

obesity and chronic diseases such as diabetes and heart diseases. The increasing number of young

people being inactive is thus discouraging. While sport participation peaks when children are 11-13

years old, dropout increases in adolescence. It is therefore essential to gain more insight into the

underlying factors that cause dropout. Perceived competence has been identified as one key

predictor. This is unsurprising as youngsters, rather naturally, tend to gravitate away from areas

where they feel unsuccessful. As such, it feels intuitive to conclude that fostering perceived

competence is effective to prevent dropout. Such assumptions have caused a shift in the sports

culture, emphasizing the idea of “verybody is a winner” Even if one is not the winner, one should

be treated as a winner and receive a medal so that feelings of competence are boosted. Yet, what

has not been investigated is whether positive appraisals of competence are also adaptive when it

leads youngsters to overestimate their own capabilities. The current project investigates the role of

overestimation of one’ personal motor competence in the prediction of persistence in, versus

dropout from sport, while simultaneously examining psychological and contextual precursors of

overestimation, hereby relying on two well-validated motivational theories (Self-Determination

Theory, Ability Beliefs Theory).