Environmental and psychosocial correlates of physical activity in Portuguese and Belgian adults

Objectives: To investigate differences in reported physical activity levels and in perceived environmental and psychosocial correlates of activity between Portuguese and Belgian adults; and to analyse the relative contribution of environmental and psychosocial variables in explaining physical activity within different contexts in Portugal and Belgium. Design: Cross-sectional study. Setting: One city in Portugal (Oeiras) and one in Belgium (Ghent). Subjects: In total 526 participants, 247 from Portugal and 279 from Belgium, completed the long International Physical Activity Questionnaire and a validated questionnaire on environmental and psychosocial correlates. Results: For the sum of all activities of at least moderate intensity, a significantly higher mean level of activity was found in Belgian adults (P < 0.001). However, comparable percentages of the Belgian (38%) and Portuguese (42%) samples did not meet the recommendation of 30 min per day. The variance explained by environmental factors was lower (1% to 8%) than by psychosocial factors (maximum 42%). Regression analyses showed activity-specific relations with environmental variables which were analogous in both countries. Walking/cycling for transportation and walking for recreation were related to social support from family and/or friends and to walkability and walking facilities in the neighbourhood. Recreational physical activity was mainly determined by social support, self-efficacy, and perceived benefits and barriers. Conclusions: Activity campaigns addressing psychosocial determinants are needed to encourage leisure-time activity, while a combination of neighbourhood design changes and encouragement of social support in walking is warranted to increase walking in different contexts.