Frontline workers are individuals whose roles require direct engagement with the public during routine and critical operations, often in unpredictable or high-stakes environments [1,2]. Although much of the empirical literature has historically focused on health care staff, broader definitions increasingly recognize that emergency responders, firefighters, police officers, transport personnel, and other essential workers also perform frontline duties that are psychologically and operationally demanding [3,4]. Across these sectors, workers operate within environments characterized by chronic stress exposure, trauma, moral responsibility, and irregular schedules, yet their contribution is fundamental to societal functioning, safety, and public health resilience [3,5,6]. Frontline workers are 23%‐39% more likely to experience clinically significant depression and 27%‐40% more likely to experience anxiety than the general population [7], with meta-analytic evidence confirming a higher prevalence of depression (31% vs 25%) and anxiety (31% vs 27%) among health care staff [6,8]. Qualitative findings further suggest that distress is often underreported due to professional expectations [9], emphasizing the need for proactive strategies to support psychological sustainability.

Growing attention is being directed toward 24-hour movement behaviors (24hrMBs), defined as the integrated pattern of sleep, sedentary time, light activity, and moderate-to-vigorous physical activity. These behaviors influence both physiological and mental health [10,11]. While higher levels of physical activity are often associated with improved mental health, occupational physical activity in manual or physically demanding roles may contribute to long-term musculoskeletal strain or fatigue, indicating that the relationship between activity levels and well-being may be more complex in certain frontline occupations [10]. Disruptions in this pattern, such as insufficient sleep or prolonged sedentary time, have been linked to heightened stress, worsened mood, and reduced well-being [12]. Frontline work presents additional challenges, including extended working hours, night shifts, rotating schedules, acute trauma exposure, and circadian misalignment (a mismatch between an individual’s internal biological rhythms and externally imposed work schedules), which can disrupt rest-activity cycles and amplify stress responses [13-15].

Complementing behavioral evidence, psychophysiological markers are objective indicators of autonomic nervous system activity and physiological stress regulation. Common measures include heart rate, heart rate variability (HRV), galvanic skin response, respiratory rate, and actigraphy-derived sleep indices, which can provide measurable indicators of stress, recovery, and autonomic regulation [16,17]. For instance, lower HRV has been consistently associated with burnout and anxiety in health care and emergency workers [18,19]. Advances in wearable and sensor-based technologies now allow continuous, ecologically valid monitoring of these markers, offering opportunities to integrate physiological and behavioral data to better understand occupational stress responses [19-21]. Psychophysiological markers captured through wearable or sensor-based technologies may reflect both acute stress responses and longer-term physiological dysregulation. For example, short-term changes in HRV, electrodermal activity/galvanic skin response, or respiratory rate may indicate immediate autonomic responses to stressors, whereas sustained alterations in resting HRV or sleep fragmentation may reflect chronic occupational strain or burnout [16,18,19].

Given the high prevalence of mental health difficulties, including burnout, posttraumatic stress disorder symptoms, emotional dysregulation, and moral injury among frontline workers [1,22], understanding how behavioral and physiological indicators interact may be critical for early detection, monitoring, and intervention. Such integration aligns with global public health priorities, including the World Health Organization’s 24-hour movement guidelines and occupational well-being frameworks, emphasizing the need for multidimensional and data-informed prevention strategies [11,23]. Despite this, research on 24hrMBs and mental health in frontline populations remains fragmented [24]. Most studies examine single behaviors (eg, sleep, exercise) rather than their interrelationships, and methodological approaches vary widely, including differences in device types, sampling protocols, and measurement techniques. Compositional data, which capture the interdependent nature of these behaviors, are rarely used, and contextual factors and adherence are inconsistently reported [24]. Similarly, psychophysiological and psychological measures of occupational stress are seldom integrated within a single analytic model, limiting understanding of how physiological dysregulation manifests behaviorally and psychologically [17,21]. Research often focuses on isolated sectors, primarily health care, underrepresenting policing, firefighting, and emergency medical services, restricting a holistic understanding of shared and unique stressors across frontline professions [3,4].

The well-being of frontline workers is increasingly recognized as a strategic priority, with the World Health Organization [5,23] advocating proactive, data-informed occupational health frameworks. Advances in wearable and sensor technologies now allow simultaneous monitoring of behavioral and physiological indicators; however, integration of 24hrMB compositions with mental health outcomes remains limited [17,20,24]. Without systematically combining these measures, the evidence base remains fragmented, hindering early identification of stress, development of proactive interventions, and establishment of integrated frameworks to enhance workforce resilience. A scoping review is therefore well-suited to map this heterogeneous evidence base. By systematically charting studies examining 24-hour movement behaviors alongside mental health indicators in frontline workers, this review will identify common measure combinations, highlight underrepresented sectors, and inform the development of integrated assessment frameworks. Ultimately, findings may guide future research, support targeted interventions, and facilitate the translation of wearable and movement-based monitoring into occupational health policy, contributing to sustainable workforce resilience.

This review aims to map research examining relationships between 24hrMBs and mental health outcomes in frontline workers, while also identifying methodological approaches used in the literature.

The primary question the review aims to answer is as follows:

The secondary questions are as follows:

As this scoping review uses only existing, publicly accessible literature and does not involve the collection of new data from human participants, formal ethical approval is not required. Nevertheless, the review will be conducted with careful attention to ethical standards for secondary research, including accurate representation of findings, proper attribution of all original sources, and transparent reporting of methods in line with PRISMA-ScR recommendations [26].

A structured three-step search strategy will be implemented following the JBI methodology for scoping reviews. An initial exploratory search was carried out via EBSCOhost using APA PsycInfo and CINAHL (full text) to identify appropriate keywords, subject headings, and search string combinations related to 24hrMBs and mental health outcomes among frontline workers. These databases were selected for their comprehensive coverage of psychology, behavioral science, physiology, occupational health, and trauma research. Insights from this preliminary search informed the refinement of search terms and the development of concept groupings encompassing movement, physiological monitoring, mental health, and frontline occupational roles. Building on this initial work, the search will be expanded to include APA PsycInfo, CINAHL, MEDLINE, SPORTDiscus, PubMed, and Scopus, ensuring coverage across health sciences as well as behavioral, occupational, and psychophysiological domains relevant to frontline workers. Gray literature will also be searched, including organizational reports (eg, NHS Scotland workforce well-being reports), policy briefs and guidance (eg, GOV.UK Wellbeing and mental health: Applying All Our Health), and technical white papers from research institutes or professional organizations (eg, British Psychological Society reports on resilience in emergency service personnel). Search terms were developed in consultation with an academic librarian and refined according to JBI guidance [32]. Draft strategies for APA PsycInfo and MEDLINE are provided in Multimedia Appendix 1, with adaptations for the other databases included in supplementary materials in the final manuscript. All retrieved references will be managed using EndNote [33] reference management software and imported into Rayyan [34], a platform designed to support collaborative article screening and study selection.

Before commencing the screening process, a calibration exercise will be conducted to ensure consistent application of inclusion criteria among reviewers [35]. Screening will follow a three-stage process: (1) title review, (2) abstract review, and (3) full-text review. Separating title and abstract screening allows rapid removal of clearly irrelevant records in large search outputs while maintaining inclusion sensitivity. Records identified as potentially relevant by at least one reviewer will progress to the subsequent screening stage. Disagreements at this stage will be resolved using an inclusion-favoring approach, in line with JBI guidance. During full-text review, two reviewers will independently assess each study against predetermined inclusion criteria encompassing population, concept, context, evidence type, and publication date. Any disagreements will be resolved through discussion, and where consensus cannot be reached, a third reviewer will adjudicate. Rayyan will be used to organize citations, document reasons for exclusion, and manage the review workflow. The final study selection process will be summarized using a PRISMA-ScR flow diagram illustrating the number of records identified, screened, excluded, and included in the review [26]. This structured approach will support methodological rigor and transparency in identifying evidence at the intersection of 24hrMBs and mental health among frontline workers [36].

Stakeholder consultation will be incorporated at multiple stages of the review to ensure the relevance and applicability of findings. Approximately 5‐10 stakeholders will be consulted, including health care professionals, occupational health researchers, and representatives from organizations supporting frontline worker well-being. Stakeholders will be identified through professional networks, research collaborators, and relevant organizational contacts with expertise in frontline occupational health or mental well-being. Consultation will occur at key stages of the review process. Early consultation will support refinement of the research questions and eligibility criteria. A second consultation stage will occur following initial data charting to gather feedback on emerging themes, the interpretation of findings, and the identification of potential gaps in the literature. Consultation will be conducted through structured meetings and email correspondence. This participatory approach aligns with the principles of co-development and supports methodological transparency, ensuring the review reflects the priorities and experiences of frontline populations [37].

Data extraction will be conducted using a standardized charting form developed in accordance with JBI guidance and tailored to the review’s research questions. The form will be piloted independently by three reviewers on a sample of 5 studies to assess clarity, completeness, and relevance. Any inconsistencies or ambiguities identified during piloting will be discussed, and the form will be refined before full data extraction. Variables extracted from included studies will be coded where appropriate to support structured synthesis across studies. Coding refers to the process of assigning extracted information to predefined analytical categories based on the data charting framework presented in Table 1, consistent with established scoping review methodology [25,38]. This approach allows information reported across studies to be systematically organized and compared during synthesis. Where study information does not clearly fit predefined categories, additional categories may be created inductively during the charting process to ensure accurate representation of the literature. For example, where studies include participants classified as “other frontline workers,” the specific occupational roles will be examined in greater detail and, where appropriate, further subcategorized during synthesis. Consistent with scoping review methodology, formal appraisal or categorization of the technical validity of wearable monitoring devices will not be undertaken [38]. Instead, information regarding the movement measurement method and monitoring devices used in each study will be extracted to provide contextual insight into the monitoring technologies represented across the literature.

Data will be synthesized descriptively using a narrative approach. Quantitative findings, such as physiological metrics and activity levels, will be summarized using tables and descriptive statistics, while qualitative data will undergo thematic analysis to identify patterns related to occupational, contextual, and experiential aspects of stress and well-being in frontline workers. The synthesis will map relationships between movement behaviors and mental health outcomes, while highlighting methodological diversity and gaps in current research. Data extraction will be conducted by three reviewers. Discrepancies will be resolved through discussion, with a fourth reviewer consulted where necessary to maintain accuracy, consistency, and reliability throughout the charting process.

Preliminary exploratory searches were conducted in October 2025 to identify relevant keywords, subject headings, and search string combinations related to 24hrMBs and mental health outcomes in frontline workers. Pilot-testing of the eligibility criteria was undertaken using a sample of studies to ensure consistent application of inclusion criteria and calibration among reviewers. Insights from this process informed refinement of the search terms and development of the final search strategy described in the Methods section. As of May 2026, updated database and supplementary searches have been completed. A total of 9874 records were identified and managed using EndNote and Rayyan. Following title screening, 3616 records were retained for abstract screening, of which 2892 progressed to full-text assessment. After full-text screening, 527 studies met the inclusion criteria and have been included for data charting. These figures are presented in a PRISMA-ScR flow diagram (Figure 1). Data charting is ongoing and synthesis is underway. Completion of the review and submission for publication are expected in July 2026.

Data charting is currently underway using the structured framework described in Table 1. The planned synthesis will describe the distribution of included studies by frontline occupation, movement behavior, measurement method, mental health outcome, study design, and occupational context. Studies will also be grouped by movement behavior domain and mental health outcome domain to support structured interpretation of a heterogeneous evidence base.

This protocol outlines a comprehensive framework for conducting a scoping review that will map the current evidence on relationships between 24hrMBs and mental health outcomes in frontline workers. The review will examine how occupational stress, trauma exposure, shift work, and job-specific demands relate to sleep, physical activity, sedentary behavior, and psychological well-being across high-stress professions, including health care, emergency services, firefighting, and policing. Previous research has often been limited in scope, focusing on specific occupational groups, isolated physiological indicators, or singular mental health outcomes [2,20]. In contrast, this review adopts a structured but inclusive approach by organizing evidence according to occupational group, movement behavior domain, mental health outcome domain, study design, evidence source type, and context. This structure is intended to preserve the breadth appropriate for a scoping review while reducing the risk that heterogeneous evidence is interpreted as a single undifferentiated body of findings. A strength of the protocol is its adherence to JBI scoping review guidance and PRISMA-ScR reporting standards, which supports transparency and reproducibility [26,32]. The search strategy is multistage and includes database searching, supplementary gray literature searching, librarian input, and pilot testing of eligibility criteria. A further strength is the explicit evidence-source plan, with empirical primary studies forming the unit of synthesis and gray literature mapped descriptively where it provides relevant empirical or practice-based information. Nevertheless, certain limitations should be acknowledged. Restricting the review to English-language publications may introduce language bias and limit global generalizability. The breadth of frontline occupations and mental health constructs may also limit comparability across studies. To address this, the synthesis will group studies by predefined domains and avoid making causal claims where study design, measurement approaches, or occupational contexts do not support them. Variations in device types, self-report measures, monitoring protocols, and definitions of movement behaviors may further limit direct comparison; therefore, findings will be interpreted descriptively using a narrative approach rather than as pooled estimates.

The findings from this scoping review will be shared through a combination of academic and nonacademic channels to maximize reach, stakeholder engagement, and practical impact. A peer-reviewed journal article will present the results, discussion, key findings, and conclusions, while a summary report will be prepared for organizational stakeholders, including health care providers, emergency services, professional associations, and policy bodies. Stakeholder-specific dissemination will include concise reports summarizing key findings, research gaps, and practical recommendations tailored to occupational health and workplace well-being priorities. Academic dissemination will include presentations at national and international conferences in psychology, occupational health, public health, and trauma research. Public engagement will be supported through accessible, open-access outputs, such as webinars, infographics, and short-form digital summaries, designed to communicate findings to frontline workers, practitioners, and policymakers. All outputs will be co-developed with frontline worker representatives and organizational partners to ensure relevance, accessibility, and applicability. Digital dissemination will leverage institutional websites, professional networks, and social media platforms to enhance visibility and reach. In alignment with open science principles, all review materials, including search strategies, data extraction templates, and synthesis tables, will be made available as supplementary files or will be deposited in open-access repositories. This approach promotes transparency, reproducibility, and knowledge sharing, enhancing the utility of the review for researchers, practitioners, and decision-makers across frontline sectors.

In summary, this protocol establishes a timely and methodologically robust approach to understanding the relationships between 24hrMBs and mental health in frontline workers. Amid growing awareness of occupational stress, burnout, and trauma exposure, the review will address existing knowledge gaps, identify priority areas for future research, and guide the design of targeted, evidence-informed interventions to support the mental health and well-being of frontline workers.