Table 2: Principal component analysis of the items in the children’s questionnaire assessing parental and friends’ influence on children’s physical activity.

Active parentsGeneral friend supportTangible parental supportFriend’s PA normsIntangible parental support

My parents or other adults who live with me, take part in physical activity with me during weekends.827
My parents or other adults who live with me, take part in physical activity with me during weekdays.809
My parents or other adults who live with me, take part in lots of physical activity during weekends.777
My parents or other adults who live with me, take part in lots of physical activity during weekdays.663

My friends, that I spend time with after school, encourage me to be physically active.797
My friends, that I spend time with after school, engage in physical activity with me in the afternoon.736
I go to a friend’s house in the afternoon to do some physical activity.718
My friends, that I spend time with after school, go out in the afternoon to do some physical activity/sport.706

My parents or other adults who live with me, transport me to a sports club in the after school period.825
My parents or other adults who live with me, pay for me to attend a sports club (e.g. soccer, swimming).780
My parents or other adults who live with me, buy for me sports clothes and other equipment relating to the sports I engage in (e.g. balls).603
My parents or other adults who live with me, watch me while engaging in physical activity (e.g. playing football, swimming).511

My friends believe that it’s a very good thing to engage in physical activity (e.g. running or playing a sport).876
My friends believe that it’s a very good thing to attend sports clubs in the afternoon (e.g. soccer, swimming).692
My friends participate in a lot of physical activities (e.g. running or playing a sport).645

My parents or other adults who live with me, encourage me to be physically active.782
My parents or other adults who live with me, talk to me about the benefits of physical activity.751

Eigenvalues2.6762.3892.2101.9371.641
Percentage of variance explained by each factor15.74314.05612.99811.3969.655
Cronbach’s alpha of each factor0.8220.7480.7000.6610.627