Aim: Occupational physical activity (OPA), and particularly static postures and physically exerting activities, is known to impact worker health and to increase the risk of cardiovascular disease, musculoskeletal problems, sickness absence and premature retirement. The exploration of structural preventive measures at the workplace against the adverse health effects of excessive OPA is needed. The psychosocial work environment is hypothesised to buffer the adverse effects of OPA, and as such psychosocial resources might directly influence the performance of OPA. However, this has not been previously investigated with detailed objective measurements. The aim of this study is to describe OPA within blue-collar workers, and to examine the role of psychosocial job resources in the performance of OPA.

Methods: Results are based on a sample of 198 blue-collar workers from the NOMAD (New method for Objective Measurements of physical Activity in Daily living) study, recruited from seven workplaces in Denmark. The sample included 112 men (56.6%) and 86 women (43.4%); the mean age was 44.9 years (SD 9.9). Data were collected with two Actigraph devices placed on the thigh and trunk, during four consecutive days. The accelerometer data were processed and analysed using the Acti4 software, to determine working time spent standing, walking, on feet and in activity of moderate to vigorous intensity level (MVPA). The level of influence and social support at work were assessed by questionnaire, and measured with a four-item scale. Analysis of (co-)variance and (multiple) linear regression models were conducted. All analyses were stratified by gender predominance of occupation.

Results: The different types of OPA significantly varied by particular job type. Within male predominant occupations, job type accounted for 50–70% of explained variance, depending on the type of OPA. Manufacturing workers showed the highest average proportions of working time standing (33%) and on feet (79%), while garbage collectors had the highest proportion of working time in MVPA (33%). Mobile plant operators and construction workers had the lowest average working time spent walking and in MVPA. Differences in OPA between job types in female predominant occupations were less pronounced, but healthcare workers and cleaners had higher average proportions of time spent walking and in MVPA compared to assembly workers. The addition of age and psychosocial resources to the models did not contribute to a larger explained variance in OPA and the relations with job type remained significant. Social support at work showed an independent positive relation with working on feet, and with standing in female predominant jobs only. Influence at work was not related to OPA.

Conclusion: The positive relation of social support with working on feet and standing is likely to be explained by the nature of the work tasks, as jobs that require these activities probably comprise more close interactions and as such create more intensified levels of cooperation at the work floor. Overall, our hypothesis that psychosocial job resources would affect the performance of OPA within blue-collar workers was not confirmed. These findings suggest that the performance of OPA within blue-collarjobs – and particularly within male predominant occupations – is mostly affected by work organisational factors related to specific job type, and not by psychosocial job resources.