Inadequate sleep is common and contributes to poor health outcomes. Physical activity has a positive impact on sleep outcomes, however the prevalence of physical inactivity is increasing, coupled with the rise of sedentary behaviour at work. Interventions that promote physical activity and reduce sedentary behaviour are essential, as they can improve sleep. The current study investigated the effects of breaking up prolonged sitting with physical activity during the day or night, compared to not breaking up sitting, on sleep architecture during a 9 h or 5 h sleep opportunity. Participants (n = 125, 51% male, 23.4 ± 4.8 years of age) completed an in-laboratory sleep study, with five simulated shifts during the day or night. Sleep opportunities were either 9 h or 5 h following each shift. Participants were allocated to one of six conditions: Sit9D or Break9D (sedentary or breaking up sitting day and 9 h sleep opportunity), Sit5D or Break5D (sedentary or breaking up sitting day and 5 h sleep opportunity), or Sit9N or Break9N (sedentary or breaking up sitting night and 9 h sleep opportunity). Sleep was monitored using polysomnography. In the analysis of day shifts, mixed model ANOVAs demonstrated a significant physical activity *sleep opportunity interaction for total sleep time (p < 0.001), sleep onset latency (p < 0.001), time spent in N2 (p < 0.001) and N3 (p = 0.03). Post-hoc analyses revealed that participants in the 9 h sleep opportunity conditions had longer total sleep time, shorter sleep onset latency, and more slow-wave sleep (N3) during sleep opportunities 1–4 but not sleep opportunity 5. There were no significant differences in sleep architecture between physical activity condition for the nightshift conditions. Better sleep quality was seen in the 9 h condition compared to the 5 h condition, and breaking up sitting did not affect sleep. Given the benefits of breaking up sitting on health, our findings suggest a breaking up sitting intervention can be promoted without detrimental impacts on sleep.

Nightshift is associated with impaired cognitive performance on many tasks, yet performance is also moderated by individual differences. We investigated the effect of circadian type (two factors: flexible-rigid, and languid-vigour), and the efficacy of a novel countermeasure, breaking up sitting with light-intensity physical activity, in the context of nightshift performance. Thirty-three healthy adults (age M ± SD: 24.3 ± 4.6 y; 19 females) participated in a sleep laboratory study over five consecutive simulated nightshifts (2200–0600 h). Sleep opportunities occurred at 0800–1700 h. Participants were randomised to a sedentary (SIT; n = 14), or “breaking-up” sitting (BREAK; n = 19) condition. BREAK participants completed 3 min of light-intensity walking every 30 min at 3.2 km/h, while SIT participants remained seated. Every 2 h during nightshift, participants completed the Psychomotor Vigilance Task (mean RRT), Stroop Task, and Digit Symbol Substitution Task. Participants completed the revised Circadian Type Inventory which categorises individuals on a rigid-flexible scale and a languid-vigorous scale (rigid; n = 12, flexible; n = 11; languid; n = 11, vigorous n = 13). Linear mixed models showed a significant 3-way interaction between Nightshifts (1–5), Condition (SIT, BREAK), and flexibility-rigidity for mean RRT (p = 0.03) only. Flexible types in the BREAK condition had better performance than rigid BREAK, rigid SIT, and flexible SIT over five nights, with performance marginally worse on the first night for all participants apart from rigid SIT. Linear mixed models showed a significant 2-way interaction between Nightshifts (1–5), and flexibility-rigidity for percentage accuracy on the Stroop task, and a significant 2-way interaction between Nightshifts (1–5), and languid-vigour for response time on the Stroop task. Accuracy worsened for rigid types, while response time on the Stroop task improved for languid types over five nights. No other significant differences were found. Breaking up sitting with light-intensity physical activity maintained sustained attention for flexible circadian types across all five experimental nightshifts. Both rigidity and languidity moderated trends in performance, though whether these differences have meaningful real-world implications must be explored further. Our results indicate that circadian type classifications should be accounted for in breaking up sitting interventions overnight.

Breaks involving physical activity may provide on-shift recovery from sleepiness and fatigue during nightshifts, with effects potentially influenced by circadian type. Thirty-three adults (M ± SD age: 24.6 ± 4.8y; 55% female) participated in five laboratory nightshifts (2200–0600h) and were randomised to sedentary (SIT; n = 14) or ‘breaking-up’ sitting (BREAK; n = 19). Participants completed the Circadian Type Inventory, categorising as rigid (n = 12) or flexible (n = 11); and languid (n = 11) or vigorous (n = 13). BREAK participants walked 3-minutes every 30-minutes at 3.2 km/h; all completed fatigue and sleepiness scales. Linear mixed models showed a 3-way interaction between nightshift (N1–N5), condition (SIT, BREAK), and rigidity-flexibility for fatigue (p<.001) and sleepiness (p<.001). Fatigue and sleepiness were greatest on N1 for SIT-Flexible and BREAK-Rigid, with SIT-Rigid experiencing the greatest levels overall. BREAK-Flexible showed no reduction. No 2-way interactions between nightshift and languidity-vigour were found. Breaking up sitting attenuated fatigue and sleepiness for rigid types only. On-shift recovery needs may differ for circadian types.

Aims: Employee-based flexible working hours are increasing, particularly among knowledge workers. Research indicates that women and men use work–time control (WTC; control over time off and daily hours) differently: while men work longer paid hours, women use WTC to counteract work–life interference. In a knowledge-worker sample, we examined associations between WTC and overtime, work–life interference and exhaustion and tested whether gender moderates the mediating role of overtime. Methods: The sample contained 2248 Swedish knowledge workers. Employing hierarchical regression modelling, we examined effects of control over time off/daily hours on subsequent overtime hours, work–life interference and exhaustion in general and in gender-stratified samples. Using conditional process analysis, we tested moderated mediation models. Results: Control over time off was related to less work–life interference (β_men= −0.117; 95% confidence interval (CI): −0.237 to 0.003; β_women= −0.253; 95% CI: −0.386 to −0.120) and lower exhaustion (β_men= −0.199; 95% CI: −0.347 to −0.051; β_women= −0.271; 95% CI: −0.443 to −0.100). For control over daily hours, estimates were close to zero. While men worked more overtime (42 min/week), we could not confirm gender moderating the indirect effect of control over time off/daily hours on work–life interference/exhaustion via overtime. Independent of gender, effects of control over time off on work–life interference were partly explained by working fewer overtime hours. Conclusions: Control over time off was related to lower exhaustion and better work–life balance (in particular for women). We found no evidence for men’s work–life interference increasing with higher WTC owing to working more overtime. Knowledge workers’ control over time off may help prevent work–life interference and burnout.

Objectives Quick returns (<11 hours of rest between shifts) have been associated with shortened sleep length and increased sleepiness, but previous efforts have failed to find effects on sleep quality or stress. A shortcom-ing of most previous research has been the reliance on subjective measures of sleep. The aim of this study was to combine diary and actigraphy data to investigate intra-individual differences in sleep length, sleep quality, sleepiness, and stress during quick returns compared to day-day transitions. Methods Of 225 nurses and assistant nurses who wore actigraphy wristbands and kept a diary of work and sleep for seven days, a subsample of 90 individuals with one observation of both a quick return and a control condition (day-day transition) was extracted. Sleep quality was assessed with actigraphy data on sleep fragmentation and subjective ratings of perceived sleep quality. Stress and sleepiness levels were rated every third hour throughout the day. Shifts were identified from self-reported working hours. Data was analyzed in multilevel models. Results Quick returns were associated with 1 hour shorter sleep length [95% confidence interval (CI)-1.23–-0.81], reduced subjective sleep quality (-0.49, 95% CI-0.69–-0.31), increased anxiety at bedtime (-0.38, 95% CI-0.69–-0.08) and increased worktime sleepiness (0.45, 95%CI 0.22– 0.71), compared to day-day transitions. Sleep fragmentation and stress ratings did not differ between conditions. Conclusions The findings of impaired sleep and increased sleepiness highlight the need for caution when sched-uling shift combinations with quick returns.

Objective: This paper discusses the past and present highlights of working hours and health research and identifies key research needs for the future. Method: We analyzed over 220 original articles and reviews on working hours and health in the Scandinavian Journal of Work, Environment & Health published during the last 50 years. Key publications from other journals were also included. Results: The majority of identified articles focussed on the effects of shift and night work, with fewer studying long and reduced working hours and work time control. We observed a transition from small-scale experimental and intensive field studies to large-scale epidemiological studies utilizing precise exposure assessment, reflecting the recent emergence of register -based datasets and the development of analytic methods and alternative study designs for randomized controlled designs. The cumulative findings provide convincing evidence that shift work and long working hours, which are often associated with night work and insufficient recovery, increase the risk of poor sleep and fatigue, sickness absence, occupational injuries, and several chronic health conditions such as cardiovascular diseases and cancer. The observed risks are strongly modified by individual and work -related factors. Conclusions: Although the observed health risks of shift work and long working hours are mostly low or moderate, the widespread prevalence of exposure and the hazardousness of the many associated potential outcomes makes such working time arrangements major occupational health risks. Further research is needed to identify exposure-response associations, especially in relation to the chronic health effects, and to elucidate underlying pathways and effective personalized intervention strategies.

Aim. To bring insights into how healthcare managers and staffing assistants work to achieve sustainable working hours within a participatory scheduling system. Background. Hospital nurses and assistant nurses often work on rotating shifts, which affects their opportunities for sleep, recovery, and work-life balance. In Sweden, a participatory scheduling approach is commonly used, where working hours are planned in collaboration between employees, managers, and staffing assistants. Influence over working hours is related to positive outcomes among shift workers. However, it also places responsibility on the employee to schedule working hours that promote health and patient safety, i.e., sustainable working hours. Accordingly, the organisation has responsibilities to support the employee in this regard. Methods. Semistructured individual interviews were conducted with 11 managers and 9 staffing assistants from four Swedish regions and analysed using thematic analysis. Results. Several key factors for achieving sustainable working hours within the context of participatory scheduling were described: distribution and clarity of responsibilities, allocating time for scheduling, establishing shared responsibility, considering fairness, fostering an individual relationship with the employee, managing dissatisfaction, providing support, clarifying guidelines for sustainable scheduling, managing inconsistencies between employee requests and sustainable working hours, and considering recovery opportunities and the competence mix on shifts. Additionally, contextual factors, such as staffing levels, working procedures, working time arrangements for night work, and technological support, were highlighted as important. Conclusion. Achieving sustainable working hours within participatory scheduling involves considering the interactions between factors at the levels of the organisation, the individual, and the technological systems. Implication for Nursing Management. Nurse managers and staffing assistants must work closely with their employees during participatory scheduling to ensure sustainable working hours. Key goals in this regard include establishing a shared responsibility, clarifying responsibilities and guidelines for sustainable scheduling, and allocating time for the scheduling process.

Short rest (<11h) between evening and day shifts – known as quick returns (QRs) – impede recovery and may impair health. Nevertheless, QRs remain popular among some shift workers. This study explores nurses’ and nursing assistants’ perceptions of the merits and demerits of QRs from individual and organizational perspectives. Participants were recruited from eleven wards at two Swedish hospitals as part of a larger quasi-experimental intervention study. The majority (79%) had influence over their work schedules. Frequency distributions of responses are presented. Ninety six undertook a baseline survey regarding recovery, tolerance and work performance in relation to QRs. A majority experienced difficulties unwinding before bedtime (76%), insufficient sleep (80%), and daytime fatigue (72%). A third experienced an increased risk of errors and mistakes. However, QRs appeared to facilitate taking reports from patients and planning work, as this task was more often rated as ‘very easy’ following a QR compared to other shift combinations. Tolerance of QRs varied substantially. In conclusion, QRs seem to benefit continuity in work processes, but may do so at the expense of recovery and safety. Wards planning to reduce QRs –through participatory or fixed schedule models – should consider impacts on work processes.

Objectives To examine if a proactive recovery intervention for newly graduated registered nurses (RNs) could prevent the development of sleep problems, burn-out, fatigue or somatic symptoms.

Methods The study was a randomised control trial with parallel design. Newly graduated RNs with less than 12 months’ work experience were eligible to participate. 461 RNs from 8 hospitals in Sweden were invited, of which 207 signed up. These were randomised to either intervention or control groups. After adjustments, 99 RNs were included in the intervention group (mean age 27.5 years, 84.7% women) and 108 in the control group (mean age 27.0 years, 90.7% women). 82 RNs in the intervention group attended a group-administered recovery programme, involving three group sessions with 2 weeks between each session, focusing on proactive strategies for sleep and recovery in relation to work stress and shift work. Effects on sleep, burn-out, fatigue and somatic symptoms were measured by questionnaires at baseline, postintervention and at 6 months follow-up.

Results Preventive effect was seen on somatic symptoms for the intervention group. Also, the intervention group showed less burn-out and fatigue symptoms at postintervention. However, these latter effects did not persist at follow-up. Participants used many of the strategies from the programme.

Conclusions A proactive, group-administered recovery programme could be helpful in strengthening recovery and preventing negative health consequences for newly graduated RNs.

Trial registration number NCT04246736.

We examined whether working rotating shifts, with or without night work, is associated with the purchase of prescribed sleep medication, and whether the association is dependent on age. Data were obtained from a longitudinal cohort study of Finnish public sector employees who responded to questions on work schedule and background characteristics in 2000, 2004 and 2008. The data were linked to national register data on redeemed prescriptions of hypnotic and sedative medications, with up to 11 years of follow-up. Age stratified Cox proportional hazard regression models were computed to examine incident use of medication comparing two groups of rotating shift workers (those working shifts that included night shifts and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Shift work with night shifts was associated with increased use of sleep medication in all age groups, after adjustments for sex, occupational status, marital status, alcohol consumption, smoking and physical activity levels (hazard ratio [HR], [95% confidence interval, CI] 1.14 [1.01-1.28] for age group <= 39 years; 1.33 [1.19-1.48] for age group 40-49 years; 1.28 [1.13-1.44] for age group >= 50 years). Shift work without nights was associated with medication use in the two older age groups (HR [95% CI] 1.14 [1.01-1.29] and 1.17 [1.05-1.31] for age groups 40-49 years and >50 years, respectively). These findings suggest that circadian disruption and older age puts rotating shift workers, and especially those who work nights, at increased risk of developing clinically significant levels of sleep problems.