Introduction

Within the office workplace, prolonged sitting is common while time spent physically active (either standing, in light intensity activity, or in moderate-to-vigorous intensity activity) is minimal [1-4]. There are several drivers for these behaviors including organizational norms, task design, policy, and individual preference [5,6]. One integral element that can promote or restrict activity is the physical environment [6,7]. Traditional building design is biased toward “human energy conservation” with many sitting options available [8]. This is of concern as there is now considerable evidence that excessive sitting, particularly sitting time accumulated in prolonged, unbroken bouts [9-11], is detrimentally associated with several health outcomes including type 2 diabetes, cardiovascular disease, and premature mortality [12,13]. Importantly, these associations are observed even in adults who meet the public health guidelines for physical activity [14,15]. Conversely, regularly interrupting sitting time is beneficially associated with biomarkers of cardiovascular health, including waist circumference, glucose and insulin [9-11]. Even just replacing some sitting with standing can substantially increase leg muscle activity [16], with corresponding health benefits [17].

‘Activity-permissive’ buildings, containing features such as visible, easily accessible, and visually appealing stairs, appealing activity permissible spaces, and amenities such as transit and bike facilities [6,7,18], may beneficially impact employees’ physical activity and sitting time, and subsequently their health and possibly work-related outcomes [19,20]. In children, a move from a traditional classroom to a purpose-built activity-permissive classroom (an enclosed 35,000 feet² space with several activity promoting features including vertical, mobile white-boards; portable video display units; and, standing desks as well as allowance of free movement during lesson plans) showed a significant and substantial increase in movement [21]. In office workers, considerable (>2 hours per 8-hour workday) reductions in workplace sitting time have been observed following the introduction of an individual-level physical environment modification (sit-stand workstation) [4,22]. However, the extent and magnitude of any such benefits for office workers following a whole-of-workplace environmental change (i.e. large, structural changes that are designed to facilitate and encourage movement) are unknown. Although evaluating the consequences of these large-scale workplace interventions is complex, a natural experiment facilitates an ecologically valid perspective of the implication(s) of such changes.

Therefore the objective of this novel natural experiment was to evaluate changes in workplace activity (i.e. standing and stepping time) and sitting time, as well as health- and work-related outcomes, in office-based workers before and after transitioning from a conventional workplace to an ‘activity-permissive’ physical workplace environment. It was hypothesized that pre-post move: sitting time would decrease; standing and stepping time would increase; health outcomes and job satisfaction would improve; and, work performance would be unchanged.

Methods

Workplaces

Pre-move.

The original workplace was two connected retrofitted hospital buildings, converted into office space that was predominantly of closed design with no standing options in offices or meeting rooms.

Post-move.

The building for the new workplace was a purpose-built (i.e., specifically designed for the research group moving to the building), activity-permissive physical environment. Building features included an internal glass enclosed staircase (with attractive views) as a main design feature (Figure 1), electric height-adjustable workstations at selected desks (faculty-only), standing-option meeting rooms and common areas, centralized supplies/printing, and an office layout that promoted vertical integration (key destinations traversed different floors). Participants received no information or education regarding the potential benefits of sitting less and moving more at work and/or how the move to the new building could facilitate this. Although participants were from a physical activity research centre, at the time of the study, the potential health impacts of prolonged sedentary behavior was just emerging in the academic literature and mainstream media.

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Figure 1. Some of the features of the new ‘activity permissive’ building.

Specific features included adjustable standing desks, café-style meeting rooms with options to sit or stand, and glass staircases to maximize light and visibility.

https://doi.org/10.1371/journal.pone.0076723.g001

Results

Twenty-seven (of 79: 34%) employees moving to the new building volunteered for the study and completed pre-move assessments. Three participants left the workplace; the remaining 24 eligible participants (18 women, mean [SD] age = 34.5 [8.1] years) all completed the post-move assessment and were included in the analyses. Participants were highly educated (75% minimum Master’s education). The distribution of faculty (n=4; 16%), staff (n=7; 29%), and graduate students (n=13; 54%) who participated was comparable to broader distribution of those employment types within the workplace (18% faculty, 39% staff, 43% graduate students out of 79). Across all participants, valid workplace data was available for 103 days (out of 104 recorded days) pre-move, and 105 days (out of 105 recorded days) post-move.

Activity, health-, and work-related outcomes are reported in Table 1. Pre-move, most workplace time on average was spent sitting (364 [SD 43.0] mins/8-hr workday or 75.9 [9.0]% of work time), followed by standing (78.2 [32.1] mins/8-hr workday) and stepping (37.7 [15.6] mins/8-hr workday), with much (55%) of the sitting time accumulated in prolonged, unbroken bouts of at least 30 minutes. Post-move, there was a significant increase in workplace standing time [+18.5, 95% CI: +1.8, +35.2 mins/8-hr workday], which was more likely due to a reduction in sitting time (-19.7, 95% CI: -42.1, +2.8 mins/8-hr workday) than changes in stepping time (+1.2, 95% CI: -6.2, +8.5 mins/8-hr workday, respectively). The individual variation of this change was considerable for these outcomes, with change varying by -158 to +74 mins/8-hr workday for sitting; -41 to +129 mins/8-hr workday for standing, and -32 to +46 mins/8-hr workday for stepping. Sitting (F(2, 21)=4.493, p=0.022) and standing (F(2,21)=4.281, p=0.028) change varied significantly by employment level, with post-hoc tests showing staff reduced their sitting time (-60.7 ± 73.6 mins/8-hr workday) and increased their standing time (+48.6 ± 56.0 mins/8-hr workday) significantly more than faculty (sitting: +21.9 ± 37.7 mins/8-hr workday; standing: -11.0 ± 23.5 mins/8-hr workday). There were no statistically significant differences between the graduate student group and the staff or faculty groups for any activity outcome. Sitting time accumulation did not vary substantially pre-post move, with non-significant changes in sitting time accumulated in prolonged, unbroken bouts (+1.9 [-32.4, 36.2] mins/8-hr workday) and in number of sit-to-stand transitions (-0.4 [95% CI -1.01, 0.21]). However, the broad confidence intervals around prolonged sitting time do not rule out meaningful changes (both beneficial and adverse) for this outcome.

There were no statistically significant changes in health-related outcomes pre-post move. However, the 95% CIs for weight (-1.1, 0.5kg), percent fat (-1.0, 0.8%), and insulin (-1.6, 17.4 pmol) do not exclude the possibility of meaningful change. For work-related outcomes, there was a small, but non-significant improvement in work-performance and job satisfaction post-move. All participants agreed/strongly agreed that they enjoyed their new workplace, while 75% agreed/strongly agreed it improved their productivity (n=5 were neutral).

Discussion

The design and construction of a new, ‘activity-permissive’ building enabled the unique opportunity to evaluate the effect of large-scale changes to the workplace on activity-, health-, and work-related outcomes. Post-move, a statistically significant increase in objectively-measured workplace standing time was observed, with a concurrent (though non-statistically significant) decrease in sitting time. Potentially meaningful effects were observed for percent body fat (beneficial) and insulin (detrimental), while both work performance and job satisfaction improved post-move. Importantly, all participants enjoyed the new workplace, and most reported an increase in self-rated productivity post-move.

Although the average changes observed were not large, there was wide individual variability for the sitting, standing, and stepping changes. The average change in sitting time observed (-20 minutes/8-hr workday or -4.1% change) was very similar to that observed following a pre-post intervention evaluating point-of-choice prompting software for reducing prolonged sitting time (-4.4% reduction in sitting time observed) [2], though substantially less than has been observed when all participants receive an individual-level physical environment modification (sit-stand workstation) [4,22]. Differences were observed by employment level, with staff having greater reductions in sitting time, and greater increases in standing time compared to faculty. This suggests that access to the flexible desks were not the primary driver for the change.

It is important to note that participants were not provided with information or education regarding the benefits of reducing prolonged workplace sitting and/or how the new building could help them achieve this. Thus, the change observed could be considered to be primarily reflective of these large-scale environmental changes. Effects may be more substantial if environmental change occurs in combination with interventions based on individual (e.g., goal setting), social (e.g., addressing cultural norms around sitting and moving at the workplace), and organizational-level (e.g., visible organizational support; policies to support standing and moving) change strategies. Such multicomponent interventions, with rigorous evaluations, are needed [4,6,19].

Interestingly, given that the new building was designed to be ‘activity-permissive’, there were minimal changes in stepping time pre-post move. This lack of significant or meaningful change in workplace stepping time is consistent with a previous workplace intervention in office workers that used a multi-component approach (incorporating individual, organizational, and individual-environmental strategies) to encourage office workers to “stand up, sit less, move more” [4]. However, this measure (workplace stepping time) evaluates just one element of physical activity. Collection of data in future research on the type of physical activity (e.g., were there changes in stair use?), and also whether activity outside of the workplace changed (i.e., did the new facilities support more active travel?) will further inform the activity benefits of the physical building design.

There are important implications of these preliminary findings for workplace health promotion, and public health more broadly [18]. Although large-scale modifications to the physical environment are expensive, once built, the intervention (i.e. the structural changes of the building) is on going, and any potential benefits impact all employees (i.e., not just research participants). Furthermore, this study suggests that such benefits may not just be limited to change in activity, but also to work-related outcomes.

Strengths of this study include the objective measurement of both activity and cardio-metabolic outcomes. However, although all employees moving to the new facility were invited to participate, the moderate (34%) response rate meant that the study was underpowered: particularly for changes in health- and work-related outcomes [4]. Changes in activity outside of the workplace were not examined. Furthermore, the sample consisted primarily of highly educated researchers and trained staff working at an academic physical activity research centre. Nevertheless, the proportion of time at the workplace spent sitting (76%, with 55% of this time accrued in prolonged bouts of at least 30 minutes) and stepping for this group was similar to that observed in more general office-based populations [1,4]. Transition to the new building was not something that could be randomized, thus the study design was a natural experiment (i.e., pre-post observational investigation without a control group for comparison). Although this design allows for the observation of workers in real world conditions, it does limit inferences regarding causality, and confounding remains a possibility - particularly given the different seasons for data collection [29].

Conclusion

This preliminary investigation provides novel objective evidence that the broader physical workplace environment can impact on workplace physical activity, with a move to an “activity-permissive” building resulting in increased workplace standing time. Further research is required to understand the long-term health and work-related impacts of this change, and to evaluate whether there are any further benefits associated with addressing the individual, social and organizational factors that impact on workplace activity across the spectrum, from sitting time through to time spent in moderate- and vigorous-intensity activity.

Acknowledgments

We thank all the participants in the study for their involvement.