Our findings demonstrate for the first time that cumulative exposure to passive jobs encourages a passive lifestyle among men. We found that men who worked in passive jobs for an average on five years had a 15% greater likelihood of low LTPA than men in non-passive jobs. This association was only partially accounted for by factors such as baseline levels of LTPA, health, socioeconomic circumstances, and other health-related behaviours.
Our findings are in agreement with earlier cross-sectional research demonstrating an association between passive work and health behaviors.9-12
However, our findings, which appear to be applicable only to men, were based on a large well-characterized occupational cohort with repeated measurements of psychosocial work environment (i.e., passive jobs) during a five-year follow-up that allowed us to study previously ignored examination of the cumulative effect of passive work on LTPA. The lack of association between passive jobs and LTPA for women is consistent with research into work-related gender inequalities in health showing that working conditions seemed to affect men somewhat more negatively, while the impact of family demands on health is greater in women.22
The choice of the LTPA measure, which not considered work-related (whether paid work or unpaid domestic chores) physical activity neither a measure of total physical activity, may have contributed to the lack of association observed since LTPA measures may categorize women as inactive when they might actually be quite active.
Several methodological issues must be considered when interpreting our findings. First, given the composition of the cohort, mostly white male office-based civil servants, there is a need for more diverse samples to extend the validity of our findings. Nonetheless, given the increased percentage of white-collar workers in affluent societies,23
this cohort may be largely representative of current workplaces. Second, we selected only working participants since once out of job the balance between time dedicated to work and non-work related activities changes, which may have health consequences. Whether and how the impact of passive jobs on sedentary behaviours persists after retirement is an important question for future research. Third, a passive job might be an indicator of physical activity at work but this is unlikely to be major confounder for office-based white-collar (non-manual) populations such as ours where physically demanding manual work is expected to be small and not to distinctly modify the amount of physical activity. Indeed, adjustment for employment grade only produced a small attenuation of the relationships. Fourth, we adjusted our analyses for baseline measures of body mass index and health status. Since these two measures can be consequences of low physical activity, adjusting for them at later phases would have adjusted the outcome for some of its effects. Fifth, our sample only included 59% of the original cohort. Incompleteness may have caused our results of the association between passive job and LTPA to be misestimated since cohort members lost to follow-up were more frequently working in passive jobs and were less physically active than the included participants.
In sum, our data from British civil servants suggest that an independent relationship exists between exposure to passive jobs and low levels of LTPA in men. Thus, our results suggest that work may have an independent, albeit relatively small, effect on life-style. Although we realize the challenges of modifying the real work environment, work factors are potentially amenable to interventions. However, work factors have previously received less attention as a potential driving force in the regulation of health-related behaviours.24,25
As physical inactivity is a leading cause of disease burden in all economically developed societies, upstream interventions that reduce dull, demotivating and unchallenging jobs may be worthy of consideration.