Effects on 24-h physical behaviors and heart rate variability during sleep of a co-created workplace intervention to promote recovery in office workers with flexible work

BACKGROUND: As flexible work arrangements (FWAs) become more common among office workers, the challenge of maintaining a healthy balance between work and recovery increases. However, studies addressing workplace interventions to promote recovery in FWAs are sparse. This study examined the effects of a co-created workplace intervention on the 24-hour composition of physical behaviors and recovery during sleep among office workers with FWAs. METHODS: A controlled intervention study was performed in a large governmental organization offering FWAs. Office workers from one unit (n = 27) participated in, (1) an individual-level course on work strategies and (2) a workgroup-level workshop to develop common rules and routines for FWAs. These activities were expected to reduce work demands, facilitate detachment after work, and promote healthier 24-hour physical behavior patterns and improve recovery during sleep. Employees from a comparable unit were included as a control group working as usual (n = 21). Physical behaviors at baseline and at a 12-month follow-up were assessed in both groups using 24-hour accelerometry for three days, together with heart rate variability indicators of recovery during sleep. We calculated time used in physical activity, inactivity and sleep in a Compositional data analysis framework, and analyzed intervention effects on these behaviors and heart rate variability indicators using repeated-measures MANOVA. RESULTS: The intervention led to, on average, 36 min more sleep per night, compared to 23 min less sleep in the control group, and the effect size was large (F = 10.87, p < 0.01, ηₚ² = 0.28). The intervention had limited effects on physical activity relative to inactivity, and on heart rate variability during sleep (interaction between time and group: p > 0.05). CONCLUSIONS: An intervention combining intervention activities at the individual and workgroup levels led to longer sleep time, indicating a behavioral effect that may promote recovery and health. The intervention did not, however, affect physical activity behaviors while awake, or heart rate variability indicators of recovery during sleep. These findings suggest that interventions targeting individual and collective work practices may influence physical behaviors and recovery. Further studies are needed to examine long-term effects in other groups of workers with flexible work.