Teun Remmers

34 | Chapter 3 Abstract Background : Physical activity (PA) enjoyment may be an important determinant of long- term habitual, self-sustained PA behavior in children. The objective of the current study was to contribute toward a better understanding of how children’s PA enjoyment is associated with PA behavior by examining the influence of age, gender, BMI, and impulsivity as theoretically hypothesized moderators of this relationship. Methods : PA was measured in 171 children (77 boys, 91 girls) using accelerometers, and PA enjoyment was assessed with the validated Physical Activity Enjoyment Scale in 9-year- old children from the KOALA Birth Cohort Study, the Netherlands. Linear regressions were fitted. Moderation was tested by adding interaction terms between PA enjoyment and the potential moderators. Results : We found a significant 3-way interaction (PA enjoyment × gender × impulsivity) for all intensities of PA behavior. In boys, impulsivity strengthened the relationship between PA enjoyment and PA behavior, whereas in girls impulsivity weakened this relationship. Conclusion : In girls, this may be explained by the relative automatic occurrence of PA behavior in impulsive girls (independent of PA enjoyment). In boys, the possibility that impulsivity is associated with hyperactivity may explain this moderation. The current study may encourage researchers to investigate these interactions in future studies.