Introduction

Previous studies have found substantial differences in the health effects of occupational (OPA) and leisure time physical activity (LTPA): LTPA is generally beneficial to health, while OPA may be detrimental. Why these differences occur is, however, so far not clear. Different time patterns of OPA and LTPA may be an explanation. Thus, we aimed to investigate the extent to which time patterns of OPA and LTPA differ in a population of blue-collar workers.

Methods

This study was conducted on a cross-sectional sample of 191 blue-collar workers from seven workplaces in Denmark. Physical activity and sedentary behavior were estimated using the Acti4 method on recordings from accelerometers (Actigraph GT3X+) worn on the thigh and trunk for four consecutive days. Time patterns of OPA and LTPA were retrieved separately for work and leisure using Exposure Variation Analysis (EVA), and expressed in terms of percentage time spent in uninterrupted periods of different durations (<1min, 1-5 min, 5-10 min, 10-30 min, 30-60 min and > 60 min) of sitting, standing, and walking. Differences between OPA and LTPA in selected EVA derivatives were tested using repeated measures ANOVA with adjustments for differences between work and leisure in total time for each activity.

Results

We found significant differences between work and leisure time for several EVA derivatives, with OPA showing a larger percentage time walking and standing in short periods (<5 min), and less percent time in prolonged sitting (>30 min) than LTPA. Apart from standing (p=.10), these differences remained significant even after adjusting for the difference between work and leisure in total time spent in each activity.

Conclusion

We found, among blue-collar workers, that the time patterns of OPA and LTPA were markedly different even after adjustment for total PA time. We suggest using EVA derivatives in future studies investigating potential associations of OPA and LTPA with health outcomes.