Temporal dynamics of sitting behavior at work.

Sitting for prolonged periods of time impairs people's health. Prior research has mainly investigated sitting behavior on an aggregate level, for example, by analyzing total sitting time per day. By contrast, taking a dynamic approach, here we conceptualize sitting behavior as a continuous chain of sit-to-stand and stand-to-sit transitions. We use multilevel time-to-event analysis to analyze the timing of these transitions. We analyze ∼30,000 objectively measured posture transitions from 156 people during work time. Results indicate that the temporal dynamics of sit-to-stand transitions differ from stand-to-sit transitions, and that people are quicker to switch postures later in the workday, and quicker to stand up after having been more active in the recent hours. We found no evidence for associations with physical fitness. Altogether, these findings provide insights into the origins of people's stand-up and sit-down decisions, show that sitting behavior is fundamentally different from exercise behavior, and provide pointers for the development of interventions.

Sitting patterns in cardiovascular disease patients compared with healthy controls and impact of cardiac rehabilitation.

PURPOSE: To identify how and when to intervene in cardiovascular disease (CVD) patients' sedentary behavior, we moved beyond studying total volume of sitting and examined sitting patterns. By analyzing the timing of stand-to-sit and sit-to-stand transitions, we compared sitting patterns (a) between CVD patients and healthy controls, and (b) before and after cardiac rehabilitation (CR). METHODS: One hundered twenty nine CVD patients and 117 age-matched healthy controls continuously wore a tri-axial thigh-worn accelerometer for 8 days (>120 000 posture transitions). CVD patients additionally wore the accelerometer directly and 2 months after CR. RESULTS: With later time of the day, both CVD patients and healthy controls sat down sooner (i.e., shorter standing episode before sitting down; HR = 1.01, 95% CI [1.011, 1.015]) and remained seated longer (HR = 0.97, CI [0.966, 0.970]). After more previous physical activity, both groups sat down later (HR = 0.97, CI [0.959, 0.977]), and patients remained seated longer (HR = 0.96; CI [0.950, 0.974]). Immediately and 2-months following CR, patients sat down later (HRpost-CR  = 0.96, CI [0.945, 0.974]; HRfollow-up  = 0.96, CI [0.948, 0.977]) and stood up sooner (HRpost-CR  = 1.04, CI [1.020, 1.051]; HRfollow-up  = 1.03, CI [1.018, 1.050]). These effects were less pronounced with older age, higher BMI, lower sedentary behavior levels, and/or higher physical activity levels at baseline. CONCLUSION: Cardiac rehabilitation programs could be optimized by targeting CVD patients' sit-to-stand transitions, by focusing on high-risk moments for prolonged sitting (i.e., in evenings and after higher-than-usual physical activity) and attending to the needs of specific patient subgroups.

Sedentary work and participation in leisure-time physical activity.

OBJECTIVE: Demanding psychosocial work characteristics, such as high job demands, can have a detrimental impact on leisure-time physical activity (LTPA), with adverse consequences for employee health and well-being. However, the mechanisms and moderators of this crossover effect are still largely unknown. We therefore aimed to identify and test potential mediating and moderating factors from within and outside the work environment. Based on the previous research, we expected job demands to be negatively related to LTPA through fatigue. In addition, we expected that job control and worktime control would attenuate the relationship between job demands and fatigue. Furthermore, we hypothesized that autonomous exercise motivation and spontaneous action planning would attenuate the relationship between fatigue and LTPA. In addition to these cross-sectional hypotheses, we expected the same effects to predict a change in LTPA in the following year. METHODS: To investigate these assumptions, a preregistered longitudinal survey study was conducted among a large sample of Dutch employees in sedentary jobs. Participants reported on the constructs of interest in 2017 and 2018 (N = 1189 and 665 respectively) and the resulting data were analyzed using path analyses. RESULTS: Our cross-sectional analyses confirm a weak indirect, negative association between job demands and LTPA, via fatigue. However, this finding was not observed in our longitudinal analyses and none of the other hypotheses were confirmed. CONCLUSION: This study shows that, among employees with relatively healthy psychosocial work characteristics (i.e., high job control), the evidence for an impact of these work characteristics on participation in LTPA is limited.

Perseverative Cognition as an Explanatory Mechanism in the Relation Between Job Demands and Sleep Quality.

PURPOSE: The aim of this longitudinal three-wave study was to examine (i) reciprocal associations among job demands, work-related perseverative cognition (PC), and sleep quality; (ii) PC as a mediator in-between job demands and sleep quality; and (iii) continuous high job demands in relation to sleep quality and work-related PC over time. METHOD: A representative sample of the Swedish working population was approached in 2010, 2012, and 2014, and 2316 respondents were included in this longitudinal full-panel survey study. Structural equation modelling was performed to analyse the temporal relations between job demands, work-related PC, and sleep quality. Additionally, a subsample (N = 1149) consisting of individuals who reported the same level of exposure to job demands during all three waves (i.e. stable high, stable moderate, or stable low job demands) was examined in relation to PC and sleep quality over time. RESULTS: Analyses showed that job demands, PC, and poor sleep quality were positively and reciprocally related. Work-related PC mediated the normal and reversed, direct across-wave relations between job demands and sleep quality. Individuals with continuous high job demands reported significantly lower sleep quality and higher work-related PC, compared to individuals with continuous moderate/low job demands. CONCLUSION: This study substantiated reciprocal relations between job demands, work-related PC, and sleep quality and supported work-related PC as an underlying mechanism of the reciprocal job demands-sleep relationship. Moreover, this study showed that chronically high job demands are a risk factor for low sleep quality.

The effect on sleep of being on-call: an experimental field study.

The aim of this study was to: (i) gain more insight into the relationship between being on-call and sleep and (ii) investigate the role of stress in this relationship. Data were collected by means of an experimental field study with a within-subject design (two conditions, random order). Ninety-six students participated during two consecutive nights: a reference night and a simulated on-call night without an actual call. Participants were told they could be called at any time during the on-call night. In the case of a call, participants had to perform online tasks for approximately 30 min. Self-reported sleep quality and the extent to which participants experienced stress during the on-call period were assessed by means of short questionnaires. Actigraphy was used to obtain objective sleep measures. Results for actigraphy data revealed no significant within-person differences between conditions. However, participants reported longer sleep onset latencies, more awakenings and more wake after sleep onset during the on-call night than during the reference night. They also reported more sleep problems and a lower overall sleep quality, and felt less recuperated after the on-call night. Perceived stress moderated the relationship between being on-call, on one hand, and the number of awakenings, wake after sleep onset, sleep problems and overall sleep quality, on the other hand. Results show that, even in the absence of an actual call, sleep during on-call nights is of lower quality and has less restorative value - especially when being on-call is experienced as stressful.

Cognitive Job Demands and Sports Participation among Young Workers: What Moderates the Relationship?

Cognitive job demands are theoretically and empirically associated with sports participation in various ways. Workers may be overwhelmed by stress and fatigue from their workload and therefore refrain from sports activities, but they can also feel the need to use sports as a way to recover and detach from work. The strategy to which workers adhere can depend on workers' resources that moderate the cognitive job demands and sports participation relationship, such as educational attainment, being a parent, or having worktime and work location control. To test our expectations, we used recent information on sports participation by young working adults from the Netherlands (N = 2032). Using multinomial logistic regression modelling, we found that workers in mentally demanding jobs were more likely to participate in sports more than three times a week. In particular, workers without children reported a higher likelihood of participating in sports more than three times a week when they experienced high cognitive job demands. Among the higher-educated, workers with high cognitive job demands were less likely to participate in sports one to three times a week. We reflect on the academic and policy-related implications of our findings.

Why do people sit? A framework for targeted behavior change.

To improve health and wellbeing, it is crucial that people regularly interrupt their sitting. In this paper, we propose a framework for examining and changing sitting behavior that addresses two key steps in the process towards developing effective interventions. First, we suggest that research should move away from its current focus on sitting time, which is an outcome of behavior. Rather, researchers should focus on stand-to-sit and sit-to-stand transitions, which are discrete units of behavior. Second, drawing on goal hierarchy models, we suggest that people rarely engage in stand-to-sit and sit-to-stand transitions for the purpose of being in a sitting or standing position; rather, we suggest that these transitions are means to higher-order goals (e.g., to complete work tasks, to watch television, to eat dinner). To improve adherence to and effectiveness of sitting behavior interventions, intervention designers should aim to increase the frequency of sit-to-stand (and stand-to-sit) transitions. To achieve this aim, intervention designers should capitalize on the higher-order goals that are typically served by these transitions. We suggest four concrete intervention strategies to increase sit-to-stand transitions in congruence with people's everyday goals. We also describe the implications of our framework for theory and methods in sitting behavior research.

The sound of stress recovery: an exploratory study of self-selected music listening after stress.

BACKGROUND: Empirical support for the notion that music listening is beneficial for stress recovery is inconclusive, potentially due to the methodological diversity with which the effects of music on stress recovery have been investigated. Little is presently known about which recovery activities are chosen by individuals for the purpose of stress recovery, and whether audio feature commonalities exist between different songs that are selected by individuals for the purpose of stress recovery. The current pre-registered study investigated whether audio feature commonalities can be extracted from self-selected songs for the purpose of stress recovery. Furthermore, the present study exploratorily examined the relationship between audio features and participants' desired recovery-related emotions while listening and after listening to self-selected music. METHODS: Participants (N = 470) completed an online survey in which they described what music they would listen to unwind from a hypothetical stressful event. Data analysis was conducted using a split-sample procedure. A k-medoid cluster analysis was conducted to identify audio feature commonalities between self-selected songs. Multiple regression analyses were conducted to examine the relationship between audio features and desired recovery emotions. RESULTS: Participants valued music listening as a recovery activity to a similar extent as watching TV, sleeping, or talking to a significant other. Cluster analyses revealed that self-selected songs for the purpose of stress recovery can be grouped into two distinct categories. The two categories of songs shared similarities in key, loudness, speechiness, acousticness, instrumentalness, liveness, musical valence, tempo, duration, and time signature, and were distinguished by danceability, energy, and mode. No audio features were significantly associated with participants' desired recovery emotions. CONCLUSIONS: Although a comprehensive portrait of the relationship between audio features and stress recovery still warrants further research, the present study provides a starting point for future enquiries into the nuanced effects of musical audio features on stress recovery.

The impact of cognitive work demands on subsequent physical activity behavior.

After cognitively demanding work, individuals tend to be less physically active. However, the psychological mechanisms underlying this effect have not been thoroughly tested. The aim of this article was to experimentally investigate the impact of cognitive work demands on subsequent physical activity behavior. Across two preregistered experiments, participants were exposed to high or low levels of cognitive work demands, operationalized as workload in Experiment 1 and as working-memory load in Experiment 2. In a subsequent choice task, participants made binary consequential choices between leisure nonphysical activities (e.g., drawing) and effortful physical activities (e.g., cycling). Choice alternatives were matched on attractiveness rankings. Additionally, physical endurance performance was measured using a standardized cycling protocol in Experiment 1. In contrast to the hypotheses, after performing work with high cognitive demands, participants were not more likely to choose nonphysical over physical activities nor did they perform significantly worse on the physical endurance task. Exploratory analyses suggest that preexisting preferences for either physical or nonphysical activities explained physical activity behavior above and beyond exposure to cognitively demanding work. These experiments question the impact of cognitively demanding work on subsequent cognitive fatigue and physical activity behavior. Implications for theory, practice, and future directions are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Music listening and stress recovery in healthy individuals: A systematic review with meta-analysis of experimental studies.

Effective stress recovery is crucial to prevent the long-term consequences of stress exposure. Studies have suggested that listening to music may be beneficial for stress reduction. Thus, music listening stands to be a promising method to promote effective recovery from exposure to daily stressors. Despite this, empirical support for this opinion has been largely equivocal. As such, to clarify the current literature, we conducted a systematic review with meta-analysis of randomized, controlled experimental studies investigating the effects of music listening on stress recovery in healthy individuals. In fourteen experimental studies, participants (N = 706) were first exposed to an acute laboratory stressor, following which they were either exposed to music or a control condition. A random-effects meta-regression with robust variance estimation demonstrated a non-significant cumulative effect of music listening on stress recovery g = 0.15, 95% CI [-0.21, 0.52], t(13) = 0.92, p = 0.374. In healthy individuals, the effects of music listening on stress recovery seemed to vary depending on musical genre, who selects the music, musical tempo, and type of stress recovery outcome. However, considering the significant heterogeneity between the modest number of included studies, no definite conclusions may currently be drawn about the effects of music listening on the short-term stress recovery process of healthy individuals. Suggestions for future research are discussed.

Correction: Protocol of the Healthy Brain Study: An accessible resource for understanding the human brain and how it dynamically and individually operates in its bio-social context.

[This corrects the article DOI: 10.1371/journal.pone.0260952.].

Investigating the associations among overtime work, health behaviors, and health: a longitudinal study among full-time employees.

BACKGROUND: It has often been suggested that high levels of overtime lead to adverse health outcomes. One mechanism that may account for this association is that working overtime leads to elevated levels of stress, which could affect worker's behavioral decisions or habits (such as smoking and lack of physical activity). In turn, this could lead to adverse health. PURPOSE: The present study examined this reasoning in a prospective longitudinal design. Data from the prospective 2-year Study on Health at Work (N = 649) were used to test our hypotheses. METHODS: Structural equation analysis was used to examine the relationships among overtime, beneficial (exercising, intake of fruit and vegetables) and risky (smoking and drinking) health behaviors, and health indicators (BMI and subjective health). RESULTS: Working overtime was longitudinally related with adverse subjective health, but not with body mass. Moreover, working overtime was associated with lower levels of physical activity and intake of fruit and vegetables, but not with smoking and drinking. Finally, higher levels of risky and lower levels of beneficial health behaviors were longitudinally associated with ill health. CONCLUSIONS: The relation between overtime and ill health is partly accounted for by the unhealthy lifestyle in which overworkers tend to engage. However, a direct longitudinal effect of overtime on health suggested that the effects of overtime on health may also partly be due to the sustained physiological activation that results from working overtime. Whereas working a moderate amount of overtime does not usually entail major health risks, these will increase with increasing overtime.

Second-order motor planning difficulties in children with developmental coordination disorder.

The second-order motor planning ability of children with developmental coordination disorder (DCD) has often been studied using tasks that require judgements of end-state comfort (ESC). In these studies, children may have chosen to prioritize other aspects of performance (e.g., a comfortable start-posture) over ESC while still being able to complete the goal of the task. This is a limitation that is inherent to previously used ESC paradigms. To avoid this in the present study, 52 children with and without DCD (aged 5-12 years) completed a task that requires second-order motor planning for its successful completion. In the hexagonal knob task, children were instructed to grasp and rotate a hexagonal knob. The rotation angle varied in size: 60°, 120°, 180°, and 240° rotations. Both the 180° and 240° rotation conditions required an uncomfortable starting posture for successful task completion. Results showed that children with DCD were less likely to adjust their initial grip in anticipation of the required rotation angle, resulting in more task failures compared with typically developing (TD) children. Based on this finding we conclude that children with DCD experience genuine second-order motor planning difficulties. Analysis of temporal outcomes, showed that initial reaction time increased with rotation angle, but this was less pronounced for children with DCD than for TD children. There were no between group differences in timing of subsequent events. These results suggest that the difficulties of children with DCD are related to the initial planning process, that is, before the start of the movement.

"20,000 leagues under the sea": Sleep, cognitive performance, and self-reported recovery status during a 67-day military submarine mission.

Employing a field-based monitoring paradigm, the current study examined day-to-day fluctuations in actigraphy-based sleep recordings, cognitive performance (10-min psychomotor vigilance test; PVT), and self-reported recovery status among 14 submariners throughout a 67-day military mission. Mission averages reflected suboptimal sleep that was of short overall duration (5:46 ± 1:29 h per 24-h day) and relatively low efficiency (82.5 ± 9.9%); suboptimal levels of cognitive performance (PVT mRT = 283 ± 35 ms; PVT response errors = 5.3 ± 4.8); and moderate levels of self-reported recovery. Whilst self-reported recovery status remained stable across mission days, small but consistent day-to-day increases in sleep onset latency and PVT mRT accumulated to reflect meaningful deterioration in sleep and cognitive performance across the entire 67-day mission (i.e., 47% and 16% of the overall mission average, respectively). Future work is required to corroborate the current findings, firmly establish underlying causes, and make evidence-based suggestions for interventions to improve and uphold submariners' health and performance.

The Impact of Cognitive and Physical Effort Exertion on Physical Effort Decisions: A Pilot Experiment.

Research suggests that cognitive fatigue has a negative impact on physical activity participation. However, the mechanisms underlying this effect are yet unclear. Using an effort-based decision-making paradigm, we examined whether individuals weigh physical effort-costs more strongly when they are cognitively or physically fatigued. Twenty university students visited the lab on three occasions. On each visit, participants underwent a manipulation that was designed to either induce cognitive fatigue (i.e., 2-back task), physical fatigue (i.e., handgrip exercise), or served as a control condition (i.e., documentary watching). After the manipulations, participants performed an effort-based decision-making task in which they decided for 125 offers whether they accepted the offer to exert the required level of physical effort to obtain rewards that varied in value. The probability to accept offers declined with increasing effort requirements whereas the general probability to accept offers was not reduced by any of the experimental conditions. As expected, the decline in accepted offers with increasing effort requirements was stronger after prolonged exertion of physical effort compared to the control condition. Unexpectedly, this effect was not found after exerting cognitive effort, and exploratory analyses revealed that the impact of physical effort exertion on physical effort-based decisions was stronger than that of cognitive effort exertion. These findings suggest that people weight future physical effort-costs more strongly after exerting physical effort, whereas we could not find any evidence for this after exerting cognitive effort. We discuss multiple explanations for this discrepancy, and outline possibilities for future research.

Working from home: mismatch between access and need in relation to work-home interference and fatigue.

OBJECTIVES: Working from home (WfH) is a promising practice that may enable employees to successfully and sustainably combine work and private life. Yet, not every employer facilitates WfH and not every employee has similar needs concerning the practice. The current study aims to examine the association of a WfH mismatch with work-home interference (WHI) and fatigue. METHODS: Data on WfH, WHI, and fatigue of a quasi-representative sample of 2374 Dutch employees in 2012/13 and a follow-up measurement one year later were used. Cross-sectional and longitudinal regression analyses were conducted to investigate the cross-sectional and temporal associations between WfH mismatch on the one hand and (changes in) time-based and strain-based WHI and fatigue on the other hand. RESULTS: In the cross-sectional analyses, WfH mismatch was significantly associated with higher time-based WHI (B=0.13), strain-based WHI (B=0.17) and more fatigue (B=0.32). WfH mismatch was not associated with changes in these outcomes after one year of follow-up. CONCLUSIONS: A tailored WfH organizational policy, in which employees' need for working from home is taken into account, may be a fruitful approach to utilize WfH as a way for employees to successfully and sustainably combine work and private life to its full potential.

'Intelligent' lockdown, intelligent effects? Results from a survey on gender (in)equality in paid work, the division of childcare and household work, and quality of life among parents in the Netherlands during the Covid-19 lockdown.

OBJECTIVE: The COVID-19 pandemic is more than a public health crisis. Lockdown measures have substantial societal effects, including a significant impact on parents with (young) children. Given the existence of persistent gender inequality prior to the pandemic, particularly among parents, it is crucial to study the societal impact of COVID-19 from a gender perspective. The objective of this paper is to use representative survey data gathered among Dutch parents in April 2020 to explore differences between mothers and fathers in three areas: paid work, the division of childcare and household tasks, and three dimensions of quality of life (leisure, work-life balance, relationship dynamics). Additionally, we explore whether changes take place in these dimensions by comparing the situation prior to the lockdown with the situation during the lockdown. METHOD: We use descriptive methods (crosstabulations) supported by multivariate modelling (linear regression modelling for continuous outcomes; linear probability modelling (LPM) for binary outcomes (0/1 outcomes); and multinomial logits for multinomial outcomes) in a cross-sectional survey design. RESULTS: Results show that the way in which parents were impacted by the COVID-19 pandemic reflects a complex gendered reality. Mothers work in essential occupations more often than fathers, report more adjustments of the times at which they work, and experience both more and less work pressure in comparison to before the lockdown. Moreover, mothers continue to do more childcare and household work than fathers, but some fathers report taking on greater shares of childcare and housework during the lockdown in comparison to before. Mothers also report a larger decline in leisure time than fathers. We find no gender differences in the propensity to work from home, in perceived work-life balance, or in relationship dynamics. CONCLUSION: In conclusion, we find that gender inequality in paid work, the division of childcare and household work, and the quality of life are evident during the first lockdown period. Specifically, we find evidence of an increase in gender inequality in relation to paid work and quality of life when comparing the situation prior to and during the lockdown, as well as a decrease in gender inequality in the division of childcare and household work. We conclude that the unique situation created by restrictive lockdown measures magnifies some gender inequalities while lessening others. DISCUSSION: The insights we provide offer key comparative evidence based on a representative, probability-based sample for understanding the broader impact of lockdown measures as we move forward in the COVID-19 pandemic. One of the limitations in this study is the cross-sectional design. Further study, in the form of a longitudinal design, will be crucial in investigating the long-term impact of the COVID-19 pandemic on gender inequality.

A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue.

This prospective four-wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand-control history on the development of sleep quality and fatigue. Based on results of a four-wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1-year time lag, supporting the strain hypothesis (Demand-Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high-strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep-related complaints. Cumulative exposure to a low-strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non-high-strain towards a high-strain job was associated with a significant increase in sleep-related complaints; conversely, a transition towards a non-high-strain job was not related to an improvement in sleep-related problems.

A diary study to open up the black box of overtime work among university faculty members.

OBJECTIVES: This study aimed at opening up the black box of overtime work among university faculty members by providing information on (i) when faculty members work overtime, (ii) what activities are undertaken during overtime, and (iii) how overtime is experienced. METHODS: Data were collected among 120 Dutch faculty members who completed a general questionnaire (addressing general overtime hours, work characteristics, and well-being) and a 9-day diary study (with information on daily overtime hours, activities, and experiences). Analyses of variance were used to analyze the data. RESULTS: Overtime was very prevalent among faculty members, high overtime workers being nonfatigued, engaged employees with positive work characteristics. Overtime was unevenly distributed over the week, being common on Sunday and Monday and uncommon on Friday and Saturday. Overtime activities during the weekend differed from those during the workweek, relatively much time being spent on research during weekend overtime. Overtime activities were experienced differently than activities during regular hours, overtime work being experienced as less effortful and less stressful than regular workhours and weekend overtime being less pleasurable than regular hours and evening overtime. CONCLUSIONS: This detailed day-to-day mapping and evaluation of overtime work contributes to a better understanding of overtime work by demonstrating meaningful patterns of overtime over the (work)week and meaningful associations between overtime activities and time-contingent experiences. It is suggested that worktime control plays an important role in explaining the results.

Distinguishing between overtime work and long workhours among full-time and part-time workers.

OBJECTIVES: This study aimed at disentangling the effects of overtime hours from those of long workhours. For part-time workers, overtime work is not intertwined with long workhours as it is for full-time workers. Therefore, part-time and full-time employees were compared with regard to the association between overtime and well-being (fatigue and work motivation). Such comparisons may also shed more light on the psychological meaning of overtime work for part-time and full-time workers. METHODS: A survey study was conducted among a representative sample of Dutch employees (N=2419). An analysis of covariance was used to investigate whether the relationship between overtime and well-being differs between marginal part-time (8-20 contractual workhours), substantial part-time (21-34 hours), and full-time (>or=35 hours) workers. Work characteristics (ie, job demands, decision latitude, and job variety), age, and gender were treated as covariates. RESULTS: No significant relationship between overtime and fatigue was found for any of the contract-hour groups. For the part-time workers, overtime was not related to higher work motivation, whereas for full-time workers it was. CONCLUSIONS: It is important to distinguish between overtime and long workhours, given the differential overtime-motivation relationship among part-time and full-time workers. This finding suggests that part-time employees work overtime for reasons other than motivation or that working overtime does not enhance work motivation for this group of employees. Overtime work seems to have a different meaning for part-time and full-time workers.