24-hour movement behavior adherence and associations with health outcomes: an umbrella review

Abstract

Background

Physical activity, sedentary behavior, and sleep, collectively known as the 24-hour movement behaviors, demonstrate individual and joint benefits on physical and mental health. Examination of these behaviors has expanded beyond guideline adherence to reviews of isotemporal substitution models (ISM) and compositional data analysis (CoDA). This umbrella review sought to review existing systematic reviews to (1) characterize the breadth and scope, (2) examine prevalence estimates for 24-hour movement guideline adherence, and (3) examine the relationship between these behaviors with health outcomes based on various approaches.

Methods

Eight databases and multiple supplementary strategies were used to identify systematic reviews, meta-analyses and pooled analyses that included two or more of the three 24-hour movement behaviors and a multi-behavior assessment approach. Overall review characteristics, movement behavior definitions, approaches, and health outcomes assessed were extracted, and methodological quality was assessed using the AMSTAR2 tool. Review characteristics (Aim 1), guideline prevalence estimates (Aim 2), and associations with health outcomes (Aim 3) were examined.

Findings

Thirty-two reviews (20 systematic reviews, 10 meta-analyses, and 2 pooled analyses) were included. Reviews captured the entire lifespan, global regions, and several physical and mental health outcomes. Individual and total guideline adherence waned from preschool to adolescence, but reviews reported similar prevalence estimates and ranges (i.e., within 10%). Common approaches included ISM and CoDA, evaluating 24-hour movement behavior’s interactive associations with health outcomes, guideline adherence, and profile-based analysis. Despite heterogeneous approaches, reviews found consistent evidence for beneficial associations between meeting all three guidelines and high amount of physical activity on physical and mental health outcomes, but varied assessment of sedentary behavior or sleep. Most reviews were rated as low or critically low quality.

Conclusions

The breadth and scope of current reviews on 24-hour movement behaviors was wide and varied in this umbrella review, including all ages and across the globe. Prevalence estimates among populations beyond children need to be synthesized. Amongst the variety of definitions and approaches, reviews found benefit from achieving healthy amounts of all three behaviors. Longitudinal multi-behavior original research studies with rigorous assessment of sleep and sedentary behavior may help improve future systematic reviews of these various approaches.

Introduction

Physical activity, sedentary behavior, and sleep, which are collectively referred to as 24-hour movement behaviors, are critical for physical and mental health across the lifespan [1,2,3,4,5,6]. These behaviors are unique, due to their mutually exclusive properties and reciprocal relationships across the 24-hour day. Their mutually exclusive properties refer to engaging in one behavior at a time, whereas their reciprocal relationship is shown in engaging in one behavior may influence amounts of other behaviors. An example of this reciprocal association is engaging in more physical activity during the day may result in additional overnight sleep [7]. Recognizing these interrelated and distinct properties, multi-behavior guidance for children’s physical activity, recreational (children and adolescents) or sedentary (young children) screen-time, and sleep, and subsequent guidelines were created from a Canadian group in 2016 [8,9,10]. These integrative guidelines mirror individual behavior guidance but propose a focus on achieving healthy amounts of all three behaviors across the course of a whole day. The early years (ages 0–5 years), child, and adolescent guidelines have since been adopted by multiple high-income countries [11, 12], low- and middle-income countries [13], and most recently, adult and older adult public health guidance has been established [14]. Since the creation of these guidelines, frameworks to advance 24-hour movement research have emerged, which has been accompanied by the application of several analytic approaches to examine associations with health beyond threshold-based guideline adherence [15]. The Viable Integrative Research in Time-Use Epidemiology (VIRTUE) Framework proposes a path forward to advance research in field of time-use epidemiology through adequately accounting for the compositional nature of 24-hour movement behaviors when investigating methods, association with outcomes, optimal time balance and prevalence, correlates of time-use, and eventual design of effective interventions [15]. As noted by others, a consensus on 24-hour-related terminology does not exist; the 24-hour movement behaviors may also be referred to as the 24-hour activity cycle, time-use behaviors, time-use activity behaviors, and physical behaviors [16]. This heterogeneity in terms and application may make gathering and comparing scientific investigations difficult, hence impeding ability to quantify the collective contribution of 24-hour movement behaviors to health outcomes and advance to eventual time-use interventions [15].

Since the release of the initial 24-Hour Movement Guidelines for Children and Youth, 24- hour movement research has grown globally; two major events occurring in 2020 may have contributed to the proliferation of research in this area. First, the World Health Organization released integrative guidelines for both physical activity and sedentary behavior, which represent key time-use components within a 24-hour day [17, 18]. However, this momentous step towards a multi-behavior focus was overshadowed by a global pandemic occurring in the same year. In early 2020, individuals began social distancing amongst the SARS COVID-19 pandemic; many were less active, spent additional time sitting, and varying changes in sleep durations and timing due to these macrosystem level changes [19]. These changes in 24-hour movement behaviors were linked to gaining additional weight and impaired mental health, especially in children, amongst multiple systematic reviews [19, 20]. These reviews also indirectly captured the increase in 24-hour movement behavior research. As shown by two separate systematic reviews, publications on 24-hour movement behaviors prior to 2020 (n = 51) [21] tripled within the year 2020–2021 alone (n = 150) [19].

This multi-behavior approach has also prompted the adoption of innovative analytic approaches to handle their collinear properties, namely isotemporal substitution modelling (ISM) and compositional data analysis (CoDA). ISM is an analytic approach that allows for hypothetical substitutions or reallocations of time across different movement behaviors within a fixed period (e.g., 24-hour day) [22]. Initial systematic reviews of studies using the ISM approach to 24-hour movement behaviors display predicted benefit from reallocating time, namely sedentary time, to moderate-to-vigorous physical activity (MVPA) and sleep on multiple physical and mental health outcomes [23, 24]. Another approach is CoDA, which was adopted from other fields [25] and first applied to 24-hour movement behaviors to examine associations with indicators of health in 2015 [26]. Application of CoDA techniques is central to the VIRTUE Framework [15]. CoDA involves transformation of behavioral data via log ratios to consider that each movement behavior represents a unique and relative (i.e., versus absolute) component of a fixed period [27]. The transformed data can then be explored as total, combined, and individual parts of the day in relation to health outcomes. Relationships with health outcomes based on these approaches may be slightly different than traditional approaches (i.e., linear regression with absolute behavioral values), as this approach considers the multicollinear nature of 24-hour time-use data, taking into account the influence of each behavior relative to time spent engaging in other behaviors [27, 28]. CoDA approach utilization has grown over the past decade, leading to subsequent reviews further exploring associations between 24-hour movement compositions and health outcomes [29], and creating a digital interface to estimate the exact reduction in health risk based on previous CoDA studies [30].

As the interest in 24-hour movement behaviors rose, so did reviews to synthesize the collective impact of these behaviors on health outcomes. Early systematic reviews assessed 24-hour movement behaviors by adherence to the child and youth 24-hour movement guidelines (i.e., physical activity duration, recreational screen-time, and sleep duration) and found the most benefit from meeting all three guidelines [31]. Though amongst the proliferation of 24-hour movement guideline adherence and CoDA, multiple reiterations of movement behaviors and approaches have emerged. For example, others have examined profile-based analysis (e.g., high physical activity, low sleep) on health outcomes [32], or conducted pooled analyses of all three behaviors using device-based measures [33].

A systematic search of existing systematic reviews is a lucrative method to characterize current evidence on 24-hour movement behavior guideline adherence, and relationships between these behaviors with health outcomes. Synthesizing the breadth and scope of these systematic reviews may help identify population and knowledge gaps for future systematic reviews and original research studies. Additionally, examining the various approaches to understand 24-hour movement behaviors in relation to health outcomes may provide detailed guidance for future reporting recommendations. Therefore, the purpose of this systematic review was two-fold: Aim 1) to characterize the breadth, and scope of systematic reviews and meta-analyses examining at least two of the physical activity, sedentary behavior, and sleep concurrently; Aim 2) examine prevalence estimates for 24-hour movement guideline adherence; Aim 3) to examine associations with health outcomes by various approaches. Together these efforts may help describe the current landscape of 24-hour movement behavior research to help harmonize investigations in the literature, identify actionable targets for future research, and focus efforts to promote appropriate amounts of all behaviors.

Methods

Search strategy

This umbrella review followed a scoping review methodology, thus follows the recommended reporting guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR, Supplemental Table 1) [34]. The protocol (i.e., research question, search strategy, inclusion/exclusion, risk of bias, data extraction items) was registered prior to the conduct of the review (registration osf.io/hwv2r). In collaboration with a librarian, the search strategy was created based on past reviews focusing on 24-hour movement behaviors with the addition of terms to obtain systematic reviews and meta-analyses [6]. There were no specific outcomes for this review (e.g., obesity), so the primary search strategy focused on the behaviors. A key component of this search was including possible grey literature and global reach, given the focus on 24-hour movement behaviors beyond high-income countries. Accordingly, we searched eight databases in total (See Supplemental Table 2). The first 6 databases were searched from inception to October 12th, 2023, including: CINAHL, Medline (EBSCO), PsychINFO, SportDiscus, Scopus, and Web of Science. The seventh (Cochrane Library) and eighth (Embase) were then searched from inception to October 24th, 2023 and October 31st, 2023, respectively. Supplemental search strategies included backward citations (searching references of included papers), forward citations (reviewing citations of the included references), reviewing published articles from a recently created 24-hour movement behavior specific journal (Journal of Activity, Sleep, and Sedentary Behavior) and international database of time-use epidemiology (International Network of Time-Use Epidemiologists), contacting experts in the field, and inclusion of gray literature.

Eligibility criteria

Detailed inclusion and exclusion criteria can be found in Table 1. In brief, systematic reviews, meta-analyses, or harmonized (pooled) data analyses were eligible if they were published in the English language, in peer-reviewed literature, or gray literature (e.g., dissertation). The population included was humans without age constraints, and the exposure was at least 2 of the 3 possible 24-hour movement constructs (physical activity, sedentary behavior, or sleep) in their research question. These constructs were created based on recognized criteria for each behavior (Table 1) [15, 35,36,37,38]. As of current, there is no consensus on terminology or reporting for 24-hour movement behaviors though many consider all three constructs a requirement for this research [15, 39]. Two constructs were allowed to accommodate related 24-hour movement terminologies (i.e., physical behaviors, which includes only physical activity and sedentary behavior) [16, 40] and current World Health Organization guidance (only physical activity and sedentary behavior) [18] as both align with 24-hour movement research, and may have guided systematic review research questions. The major topics explored in each aim were breadth and scope, prevalence estimates, and associations with health outcomes, respectively. Health outcomes were not required for Aim 1 or 2. The outcomes for Aim 3 included physical (e.g., obesity) or mental health (e.g., quality of life) outcomes.

Table 1 Detailed inclusion and exclusion criteria for review

Articles were excluded if they were in a language other than English, a form other than systematic review (e.g., narrative review, commentary, book chapter, etc.), or included animal studies within the review. The original references for country-specific 24-hour movement guidelines were excluded if their systematic review process was not documented in detail in the current article. However, if they referenced another article with additional detail on their systematic review process, the referenced article was then retrieved for consideration. Beyond article type and population, there were five other main exclusion reasons starting from study design, behaviors included, and outcomes. These main exclusion reasons were operationalized as reviews focused on (1) solely interventions to change 24-hour movement behaviors (e.g., school-based interventions to improve physical activity and limit sitting) [41], (2) methods to assess 24-hour movement behaviors (e.g., quality assessment of methods) [42], (3) only one behavior assessed [43], (4) different investigation of movement behaviors as either part of a cluster of modifiable factors [44], correlates of movement behaviors [45], or as the outcome (e.g., ambient air quality impacting physical activity or sedentary behavior) [46], and (5) investigating the association between movement behaviors with another health behavior (e.g., alcohol consumption), amongst themselves [47], or other health marker (e.g., energy compensation) [48] as an outcome.

Study selection

Abstract and full-text screening stages were performed by eight independent reviewers (CLK, SB, CWSL, CDPf, GMB, CG, CDPo, DMYB) in duplicate, and conflicts were resolved by a third reviewer. A pre-piloted protocol for both stages was created prior to study selection. Reviewers reached > 80% agreement prior to completing both stages. Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia) was used to facilitate study flow for abstract and full text screening, and subsequent data extraction.

Data extraction and critical appraisal

Data extracted was related to article information (author, year of publication), review question, population included, 24-hour movement behavior definitions, approaches, health outcome definitions, prevalence estimates of meeting public health guidelines for each movement behavior, relationships between movement behaviors (in total and individually) with health outcomes, overall results, proposed future directions, and information related to review quality and risk of bias. This information was curated based on past reviews and expert opinions, as experts (n = 10) were asked to provide input on extraction items when surveyed for additional reviews. Data was extracted in duplicate by independent reviewers and disagreements were resolved by a third reviewer.

The Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 was used as a critical appraisal tool for the included systematic reviews and meta-analyses [49]. Pooled analyses were graded but no total score was assigned. This tool assesses seven critical domains of the review including (1) protocol registration, (2) appropriateness of literature search, (3) exclusion reasons, (4) risk of bias for the included studies, (5) meta-analysis methods (when applicable), (6) interpretation of risk of bias, and (7) publication bias assessment. AMSTAR-2 scores were categorized based on number of critical and non-critical weaknesses, with categories ranging from “high " (no critical or non-critical weaknesses), “moderate” (no critical weaknesses, with one or more non-critical weakness), “low” (one critical weakness and multiple non-critical weaknesses), or “critically low” (multiple critical and non-critical weaknesses).

Synthesis of results

For Aim 1, a numerical analysis (central tendencies) related to population included, and review conduct. Countries included in systematic reviews were classified into regions based on updated World Health Organization region guidance [50]. Reviews were further described by their AMSTAR 2 quality rating (critically low, low, moderate, and high). For Aim 2, prevalence estimates for meeting individual and total guidelines were extracted and compared. A meta meta-analysis was not conducted with prevalence estimates due to significant study overlap; rather, each review’s calculated estimates are described as reported by authors. For Aim 3 reviews that assessed the relationship between 24-hour movement behaviors and health outcomes were included. Within these reviews, a qualitative description of 24-hour movement behavior terminology and approaches used, associations between movement behaviors with health outcomes, health outcome definitions, and review findings was conducted.

Results

The initial search yielded 1,841 references, of which 1,037 were removed as duplications (Figs. 1). After the title and abstract screening of 804 references, the remaining 104 full texts were considered for inclusion. Supplementary methods identified an additional 1,535 references, namely via citation searching, which resulted in 30 additional full texts for consideration (133 full texts total). Reviews could be excluded for multiple reasons, but based on the first reason many references were removed at the full-text stage for being the wrong article type (n = 42) or wrong investigation of behaviors (e.g., behaviors as outcomes, n = 25, Supplemental Table 3). The final sample included 32 reviews comprising 20 systematic reviews, 10 meta-analyses, and two pooled analyses. Review funding sources and conflicts of interests are presented in Supplemental Table 4.

Fig. 1

PRISMA 2020 flow diagram for new systematic reviews which included searches of databases, registers and other sources From: Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. doi: https://doi.org/10.1136/bmj.n71. For more information, visit: http://www.prisma-statement.org/

Aim 1: breadth and scope of reviews

An overview of the population and behaviors included is provided in Table 2. The 32 reviews included a median of 26 studies (range: 5-141 studies) and compared 4,785,140 participants in total. All ages were represented in this umbrella review, with some reviews including all ages (5/32), or only children and adolescents (ages 3-17 [51−53] or 5–17 years) [19, 54,55,56,57,58,59]. Other age groups explored across the lifespan were young children (0–5 years) [29, 31, 60], college/university students (ages ∼ 18–25 years) [61], and older adults (mean age ≥ 60 years) [62, 63]. Populations were also defined by nationality, location, and occupation, including: immigrant children [54], children and adolescents from Arabic countries [64], and airline pilots [65]. Population definitions were rarely confined to health or disease status, such as only including healthy populations [32, 60, 62, 66], or individuals with type 1 diabetes [55]. Beyond population characteristics, the time frame was another consideration as four reviews were specific to the COVID-19 pandemic [19, 20, 67, 68], while one review specifically excluded COVID-19 studies [51]. Finally, all reviews assessed physical activity, and most reviews assessed all three behaviors (physical activity, sedentary behavior or screen-time, and sleep, 26/32). Thirty reviews assessed sedentary behavior, of which three specifically did not assess screen-time [33, 65, 66], nine reviews explicitly allowed screen-time as either a sedentary behavior indicator or separate behavior [19, 21, 51, 52, 55, 56, 59, 60, 69], and the remaining 18 reviews did not clearly state if screen-time would be considered in their review (See Supplemental Table 5).

Table 2 Characteristics of included reviews related to 24-hour movement behaviors (n = 32)

As for review conduct, most reviews were registered and noted all study designs were eligible (≥ 20/32, Table 2). The median number of scientific databases searched was 4 (range: 3–14), which were searched from inception and six reviews searched since the guidelines were created in 2015 or 2016. All reviews searched MEDLINE or Pubmed, followed closely by six databases: Embase (21/32), PsychINFO (20/32), SportDiscuss (18/32), Scopus (16/32), CINAHL (12/32) or Web of Science (11/32). Less than ten reviews searched Cochrane Libraries (4/32), specific gray literature sources (e.g., ProQuest, 1/32), or other search engines. Reviews obtained a median of 26 studies (range: 5-141), including studies conducted in predominately high-income western countries (e.g., Australia, Canada, United States), east or southeast Asia (e.g., China, Malaysia, Thailand), or Latin America and the Caribbean (e.g., Bahamas, Brazil, Chile, ), though four reviews did not report the country where their retrieved studies occurred (Table 2) [24, 52, 62, 66]. Most reviews were published in 2023 (12/32), or between 2020 and 2022 (14/32). Details of included reviews in can be found in Supplemental Table 5.

Methodological quality

Thirty reviews were given overall ratings based on critical and non-critical domains, as the two pooled analyses were not given an overall rating. One systematic review [23] and one meta-analysis [51] were rated as “moderate” quality, indicating no critical weaknesses and few non-critical weaknesses. In contrast, due to the high number of critical weaknesses, seven reviews were rated as “low” [4, 31, 57, 59, 63, 68, 70], and the remaining 21 reviews were rated as “critically low” quality. Beginning with critical domains, most reviews achieved the partial or full standard for review methods (22/30 reviews), search strategy (30/32 reviews), risk of bias tool (26/32 reviews), or statistical methods (10/12 meta-analyses), but few provided a list of excluded studies with reasons (5/32 reviews) or assessed publication bias (4/12 meta-analyses). As for non-critical domains, about half of reviews met standards for delineating participant, intervention/exposure, comparator, and outcome, describing included studies, study selection, and reporting authors conflict of interest (≥ 19/32 reviews for each). Few reviews met the non-critical domains of clarifying study designs included (6/32 reviews), reporting funding for included studies (0/32 reviews), and risk of bias assessment in analysis (2/12 meta-analyses). Critical and non-critical domain scores for individual reviews are displayed in Supplemental Table 6.

Aim 2: prevalence of meeting 24-hour movement guidelines

Prevalence estimates were focused primarily on children and youth or during the pandemic, and only two reviews reported estimates for adults. As shown in Supplemental Table 7, estimates from the seven reviews that reported prevalence estimates for children and youth were derived from a median of 17 studies (range: 1–63 studies). Most child prevalence estimates were calculated based on the Canadian 24-hour movement guidelines (5/6), [21, 51, 56, 60, 68] with only one review using another guideline definition (i.e., > 20 min of vigorous intensity physical activity or > 30 min of moderate physical activity, > 3 days/week)[54] In general, reviews found around half of children met the physical activity guideline (estimate range: 22.3–67%), less than a third met the screen-time guideline (estimate range: 10-28.3%), and half or more met the sleep guideline (estimate range: 57-83.5%, Supplemental Table 7 and Fig. 2). Some children (estimate range: 7-28.6%) met 0 guidelines, a third each met 1 or 2 guidelines (estimate range: 27.7–50.6%), and few met al.l the guidelines (estimate range: 3.5–12.8, Supplemental Table 7 and Fig. 2). Individual and total guideline adherence waned from preschool to adolescence. Two reviews that assessed behaviors during the COVID-19 pandemic documented slightly lower prevalence estimates for physical activity [68], sleep [68], and meeting all three guidelines [20]. These similarities are not without caution; the three meta-analyses pooled estimates revealed high heterogeneity amongst their individual studies (i² > 95)[51, 60, 68]. In addition to children, one systematic review and one pooled analysis assessed prevalence of 24-hour movement behaviors in adults, including in airline pilots and UK adults before and during the COVID-19 pandemic [65, 67]. These reviews used different metrics for insufficient activity (i.e., not meeting physical activity guidelines), which resulted in ranges of 51.3–51.7% for airline pilots (< 150 min/week of MVPA, 5 studies, 2233 participants), [65] and 21.2–49.9% for adults pre-COVID-19 and 20-42.3% for adults during the COVID-19 pandemic (≤ 3days of at least 30 min/day of exercise, 6 studies, 19,331 participants) [67]. Similar sleep guidelines were used for insufficient sleep, which found 22% prevalence in airline pilots (< 6 h/night, 3 studies, sample size not reported) [65] and various ranges for adults pre-COVID-19 (< 6 h or 9 + hours/night, range: 6.8–14.5%, 6 studies, 19,331 participants) and during the COVID-19 pandemic (12.2–29.9%) [67].

Fig. 2

Review-calculated proportion meeting respective guidelines. Panel A: Number of Guidelines; Panel B: Specific Guidelines Panel A: ^ denotes estimates that were recalculated to proportion met as they were reported as proportion who did not meet the guidelines; gray circle = 0 guidelines; black circle = 1 guideline; black square = 2 guidelines; gray square = 3 guidelines; Panel B: *Ahmed, 2021 physical activity guidelines used was " >20min of Vigorous intensity physical activity or > 30min of moderate physical activity, > 3 days/week”, sleep guideline was not clearly defined; ∼ denotes studies during SARS COVID-19 pandemic status; black triangle = physical activity guideline; gray triangle = screen-time guideline; black diamond = sleep guideline

Aim 3: associations between 24-hour movement behaviors with health outcomes

Twenty-six studies were included in this Aim. An overview of review characteristics is presented in Table 3, and review details are documented in Supplemental Tables 8 and 9. These reviews predominantly approached 24-hour movement behaviors using ISM or CoDA techniques, evaluating 24-hour movement behavior’s interactive associations with health outcomes, guideline adherence, and created profile-based groups based on level of engagement in 24-hour movement behaviors (e.g., high PA and low SB groups). Only three of the ISM reviews specifically focused on studies using the compositional ISM approach [4, 29, 30], and the five other ISM reviews included both compositional and traditional ISM approaches [23, 24, 58, 66, 70]. Reviews primarily assessed physical health outcomes (22/26). Overwhelmingly (≥ 11/26), many reviews assessed weight, cardiometabolic health markers, and fitness, and six reviews also included mortality [4, 23, 30, 32, 33, 70]. Reviews included a median of 26 studies (range: 5-141 studies), including a median of 21 cross-sectional (range: 0-119), and 5 longitudinal studies (range:0–25). Three reviews found no longitudinal studies [32, 56, 61, 62], and eight reviews included other study designs [19, 30, 31, 53, 55, 61, 64, 69], like results of an MVPA intervention on feelings of energy [61]. Reviews assessed study quality and risk of bias of included articles through differing tools with or without modifications (e.g., Down’s and Black, Cochrane Library Risk of Bias tool, modified checklist based on reporting standards), resulting in diverse distributions of high- and low-quality articles. Notably, all six reviews that used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool to assess level of evidence found “low” or “very low” quality of evidence for their health outcome, mainly due to serious risk of bias and inconsistency [4, 31, 56, 57, 63].

Table 3 Characteristics of included reviews related to 24-hour movement behaviors and health outcomes (n = 26)

Physical activity, sedentary behavior, and sleep were clearly defined in less than a third of the reviews (see Supplemental Table 8). For physical activity, five reviews utilized the Caspersen definition of physical activity movement (“any bodily movement produced by skeletal muscles that results in caloric expenditure”) [35] or metabolic equivalent of task (MET) intensity (> 3.0 METs) [4, 29, 57, 63, 64], and two reviews defined it as sedentary screen-time [56]. Similarly, sedentary behavior was defined by wake-time MET intensity (< 1.5 MET) and sitting, standing, or reclining state as well [4, 29, 56, 64], and two reviews defined it as sedentary screen-time [56] or non-screen and screen-based sedentary behaviors [55]. Sleep was defined broadly, including altered consciousness, inhibition of muscles and reduced interactions; [64] and MET intensity (∼ 1) [63]. One review defined physical activity or sedentary behavior by any activity, time, or type; [32] another review defined each behavior based on the Canadian Society for Exercise Physiology 24-hour movement guidelines [71]. Other reviews indirectly defined these behaviors by solely including device-based measures for physical activity and sedentary behavior [66, 70], or only physical activity [23, 53]. One third of reviews did not define measurements (e.g., device-based only, device and questionnaire) as part of their inclusion criteria for physical activity (6/27), sedentary behavior (9/27), or sleep (9/27). Two reviews [66, 70] and the pooled analyses [33] were confined to only device-based measures, as all others considered device, questionnaire, or other measures for 24-hour movement behavior assessment (Supplementary Table 8). These heterogenous terminologies and methods precluded detailed investigation into how these various components may have influenced reviews findings, but overall results were qualitatively compared.

Interactive behavior examinations were common. Higher amounts of MVPA were favorable for child weight-related outcomes [64], child fitness [53], young child motor skills [60], and mortality [33]. This evidence was replicated in ISM reviews, where reallocating sedentary time to MVPA was related to favorable changes in weight [23, 24, 58], cardiometabolic health [58, 66, 70], fitness [4, 23], and mortality [4, 23, 33, 70]. These results were not always replicated when replacing sedentary time for light physical activity for weight-related outcomes [4, 24, 58] or fitness [58], but one review found evidence for waist circumference and fasting insulin [70]. Favorable results for increased amounts of MVPA on child depression [64], adult quality of life [55, 63], and other child mental health indicators were also found [71]. Accordingly, one ISM review found reallocating sedentary time to MVPA was related to favorable adult mental health [23]. The remaining behaviors of sedentary time and sleep had fewer comparisons, and results were mixed based on outcomes. Unfavorable results from high amounts of sedentary time were found for child fitness; [53, 64] while others found null or mixed results for adult cardiometabolic health markers [55, 66]. Chastin et al.’s pooled analysis found associations between the ratio of light physical activity and sedentary time to mortality in hip-measured accelerometer studies, but not wrist-measured studies [33]. One ISM review reported unfavorable results for hypothetically substituting MVPA to sedentary time on weight and mortality [4]. Better sleep, either sleep quality or duration, was associated with favorable results for depression and anxiety in individuals with type 1 diabetes [55] and adult fatigue/energy [61]. Mixed (i.e., some favorable, some null) or overall null associations were found between better sleep and young child [60] and child weight [64], and HbA1c in individuals with type 1 diabetes [55]. Substituting time in sleep to other behaviors had a null effect on weight [4, 30], cardiometabolic health markers [30], fitness [53], and mortality [4, 33].

Behaviors were also classified by adherence to the 24-hour movement guidelines or amongst profile-based groups. Meeting all three guidelines was associated with favorable child weight-related outcomes [21, 52, 69], but these results did not translate consistently to toddlers [60] and preschoolers [60, 69]. Meeting all three guidelines was associated with favorable associations for young children’s motor skills [60], children’s cardiometabolic health markers, fitness, cognition, and mental health [21], and adolescent depression [56]. Few reviews evaluated meeting one or two guidelines, or dose response associations of meeting an increasing number of guidelines on health outcomes. Kuzik et al. found favorable results with meeting two guidelines of various iterations on young child weight, fitness and motor skills [31], but Feng et al. found an overall null effect for young child weight for those who met two guidelines [60]. Feng et al. also reported a mixed association between meeting more guidelines and young child weight, and null associations of meeting the screen-time guideline and young child weight [60]. Reviews that focused on classifications of physical activity, sedentary behavior, and sleep or 24-hour movement composition found similar results [29]. Children with high amounts of physical activity, low amounts of sedentary behavior, and longer sleep had favorable weight-related [57] and mental health outcomes [59]. Mellow et al. found only two studies that explored all three behaviors with older adult cognition, though their results generally support adequate amounts of all three behaviors [62]. Duncan et al. further explored the effect of physical activity and sleep on mortality to find that high levels of physical activity may reduce mortality risk in the presence of short sleep [32].

Discussion

This review’s purpose was to characterize the breadth and scope of current 24-hour movement behavior reviews, examine prevalence estimates for 24-hour movement guideline adherence, and examine the association between these behaviors and health outcomes by differing approaches. The current landscape of systematic reviews has spanned all ages, global regions, and study designs, but in contrasting amounts and low or critically low systematic review quality. Differing approaches to 24-hour movement behavior research provide an opportunity to answer unique questions regarding the collective influence of these behaviors on health, further deepening our understanding of the implications of behavioral time-use across the course of a 24-hour day. High amounts of MVPA, reallocating sedentary behavior to MVPA, and meeting all three 24-hour movement guidelines demonstrated clear health benefit, with less certainty for sedentary behavior and sleep. This review demonstrates that systematic reviews, and hence our understanding, of the influence of 24-hour movement behaviors on health is in its nascency, with opportunities to increase future review’s representation, rigor, and reporting.

The breadth and scope of current 24-hour movement behavior research is wide across ages, regions, and time frames (i.e., pre-COVID-19 and COVID-19), proving to be both a positive and negative quality. On the one hand, multiple ages, regions, and time periods were represented; on the other hand, this vast scope was not consistent across reviews (i.e., some only captured predominately high-income countries in a narrow age range) [29] and was conducted with varying rigor. Global representation is a key issue within behavioral research [72], as findings from predominately high-income western country may not translate to other geographical regions. A review focusing specifically on children from Arab-Speaking countries exemplified this consideration by solely investigating a specific region (i.e., Central Asia, Middle East, and North Africa) [64]. Few other reviews studied subpopulations as most reviews aligned with the early guidelines for children and adolescents [8, 9], and no reviews focused on the recent adult or older adult guidelines [14]. One review attempted to examine older adult literature but found few articles with all three behaviors [62]. This disparity is likely due to few papers using these standards, or current studies still using past individual guideline stipulations [73, 74], as demonstrated in the retrieved adult prevalence reviews [65, 67]. Guideline adherence and overall investigation during the COVID-19 pandemic was minor [19, 20, 67, 68], but this time period may continue to be a consideration as further systematic reviews are conducted from database inception.

Despite the many approaches used, these 24-hour movement behavior reviews consistently found high amounts of MVPA and meeting all three guidelines were beneficial for various indicators of health. The current yield of systematic reviews also found more reviews investigated physical health outcomes relative to mental health outcomes. The most explored outcome was weight, which may be due to the relative ease of obtaining this measure, and continuing increase in childhood obesity prevalence over the past decades [75]. Poor mental health, especially in youth, is another public health concern which was brought to the forefront amongst changes in all three behaviors during the COVID-19 pandemic [19, 76]. Even so, reviews focused on mental health were less represented in this population, but are deserving of more attention. Since this current umbrella review’s search, another systematic review examined 24-hour movement behavior’s association with indicators of mental health and wellbeing has been published; [6] this new publication and others is promising for mental health receiving additional attention. Future reviews into less represented outcomes, such as bone health, functional measurements, stress, and coping may help expand our understanding of the entire 24-hour day for tailored interventions.

Consistent prevalence estimates and ranges (i.e., within 10%) were represented in adherence to individual and total guidelines across childhood. Notably, these multi-behavior results align with the original guidelines created based on single behavior investigations [1,2,3, 5]. Consistent support for high MVPA with improved health outcomes also aligns with existing evidence-based guidelines [18, 73], and general agreement for all reviews assessing the aerobic component of the guidelines (MVPA) rather than muscle-strengthening. These consistent standards and results did not translate to sedentary behavior or sleep. Excess wake time spent sedentary (MET value ≤ 1.5) is associated with poor health outcomes [77, 78], with pronounced impacts amongst those achieving lower amounts of MVPA [79], when considered as TV [80] or sedentary screen-viewing time [81], or using hip-mounted device-based measures compared to wrist-worn devices [33]. These intricacies were rarely addressed or defined in the current reviews, as exemplified by few reviews providing exact definitions for sedentary behavior, including wakeful state, MET value, and posture, or their inclusion of screen-time. These findings are disappointing as there have been agreed upon terminology for sedentary behavior and related states for almost a decade; moreover, these terms are a key consideration of existing frameworks and guidelines [15, 36]. These behavior nuances also translate to sleep, which may be considered based on duration, quality, timing, and many other metrics [77]. The metrics may not be considered amongst most approaches which solely focus on duration-based time-use estimates, whereas approaches using other groupings may consider the negative synergistic effects and other context considerations of low physical activity and poor sleep on health [31, 32, 82].

The critically low quality of reviews must be acknowledged in our consideration of movement behaviors in relation to physical and mental health outcomes. Though many areas could be improved, it is important to consider these two main areas: (1) not clearly describing eligible study designs and (2) assessing various sources of bias. Reviews predominately included all study designs, which may prevent utilizing this practice. This wide inclusion criteria may be able to capture a larger yield of articles in a growing landscape; this wide inclusion criteria may also be problematic in terms of introducing heterogeneity. Reviews conducted prior to 2020 likely had fewer studies available [21], but recent reviews did not improve this practice. The second area of consideration was evaluating and assessing publication and risk of bias amongst these retrieved studies. Without assessing these areas, it is unclear if meta-analytic results can be attributed to balanced, high-quality studies.

Strengths of the current review include the inclusion of a novel field of inquiry, rigorous review strategy by following review best practices [49], and timely evaluation as we approach a decade with the 24-hour movement guidelines. This review is not without limitations, namely confined to review conduct and topic matter considerations. The review conduct considerations include search date, English language stipulations, and included all three behaviors, which may impact inclusion of recent (published in 2024) [6, 83], non-English language reviews, and dual behavior studies. These limitations were addressed through a comprehensive search strategy of international experts and a leading international database (International Network of Time-Use Epidemiologists) to ensure all reviews that met these standards were included. The topic matter considerations are diverse approaches of included reviews, and restricted clinical utility of a hypothetical substitution approach. These considerations hinder major statements on the association between 24-hour movement behaviors and health outcomes but improve our understanding of 24-hour movement behaviors in differing ways (e.g., optimal amount, trends, and prevalence) [15]. Moreover, individual behavior focused reviews were not included in this review [84, 85], which may curb our prevalence estimates and understanding of individual behaviors. This review contributes to evidence of the current breadth and scope of reviews that included multiple 24-hour movement behaviors, and the relationship with these multiple behaviors and health outcomes.

Results of this review posit four major improvements in future research conduct and study design. First, multi-behavior longitudinal studies are warranted to enhance the quality of existing evidence. These secondary data analyses and future studies will only be helpful if agreed upon terms and reporting of 24-hour movement behaviors is achieved, which can in turn advance existing frameworks in this area [15]. Therefore, the second area is potential creation of reporting practices for 24-hour movement behaviors approaches, such as CoDA, guidelines adherence, and interactive associations, through an iterative process with experts and end-users. Beyond the number of guidelines achieved or correctly classifying approaches (i.e., individual behaviors evaluated collectively, guidelines), an activity [86] or movement index [87] allows characterizing of multiple behaviors and investigation in eventual 24-hour interventions [88]. Alignment of terminology also should be accompanied by assessment method, as there are challenge and opportunities to self-report and device-based methods for quantifying 24-hour movement behavior. Dissemination and wide-spread adoption of such approaches and possible reporting checklists is paramount, as evidenced by few reviews using existing guidance for sedentary behavior terminology [36]. The third area of improvement is conducting systematic reviews evaluating the prevalence and benefit of 24-hour behaviors amongst special populations not currently represented in the literature, including individuals with physical and developmental disabilities [89, 90], and pregnant or postpartum individuals [91, 92], as they report even lower adherence to all three guidelines. These efforts should also support review approaches to improve inclusion globally and research initiatives to expand to lesser represented regions [93]. Finally, future reviews should consider consulting existing standards for high quality systematic reviews and meta-analyses [49] to vastly improve the current scenery of poor-quality reviews.

This umbrella review revealed that the breadth and scope of existing literature on 24-hour movement behaviors is wide; this literature spans all ages and regions in different capacities. Included reviews permitted many definitions and approaches to analyzing associations between 24-hour movement behaviors and health outcomes and were overall low quality; both qualities hindered harmonized synthesis. Amongst these weaknesses, a consistent finding was improved health benefit from additional MVPA and meeting all three guidelines, with inconsistent findings for sedentary behavior and sleep. Given the collective and individual benefit of these behaviors, the next decade should focus on harmonized rigorous research using a multi-behavior approach to improve existing evidence.