The ProPASS Consortium: Movement Composition and Health Outcomes

The Significance of ProPASS (Prospective Physical Activity, Sitting, and Sleep)

For much of the history of physical activity research, scientists studied movement behaviors in isolation. One body of research examined exercise, another examined sleep, and yet another examined sedentary time. This siloed approach created an evidence base that was, in a very real sense, physiologically incomplete. A human being cannot exercise more without taking time from something else in the 24-hour day, whether that is sleep, sitting, standing, or light activity. Recognizing this fundamental interdependence, an international group of researchers established the Prospective Physical Activity, Sitting and Sleep consortium, known as ProPASS, in 2017 . The consortium was built on the premise that physical activity, sedentary behavior, and sleep are not separate lifestyle choices but interconnected components of a single 24-hour movement composition, and that understanding their combined effects on health required a collaborative, multi-cohort, device-based approach that no single study could achieve alone .

Goals

ProPASS was established with several explicit objectives . The primary scientific aim was to explore the effects of multi-dimensional 24-hour physical activity, posture, and sleep patterns on a wide range of health outcomes. To achieve this, the consortium aimed to establish a pooled data resource of unprecedented scale, bringing together individual participant data from cohort studies across multiple countries that used thigh-worn accelerometry devices. The consortium also sought to develop standardized methods for processing, harmonizing, and pooling wearable device data so that different cohorts could be analyzed together despite variations in their original protocols. A further goal was to expand the evidence base to under-represented countries, including low- and middle-income nations, and to generate the device-based evidence necessary to inform the next generation of physical activity guidelines, moving them beyond self-reported exercise toward objectively measured 24-hour behavior patterns.

Key Eye-Opening Findings

The consortium's analyses have produced a series of findings that collectively reshape how movement and health should be understood. The most fundamental is that moderate-to-vigorous physical activity demonstrates the strongest and most time-efficient protective associations with cardiometabolic outcomes, but the benefits depend on what activity it replaces . Reallocating just 30 minutes from sitting, standing, light activity, or sleep into moderate-to-vigorous activity is associated with a lower BMI, but the magnitude of benefit varies substantially depending on the source behavior. A second critical finding is that sleep quality matters as much as sleep quantity for cardiometabolic health: sleep irregularity and low sleep efficiency are associated with worse cardiometabolic risk scores, even when sleep duration is adequate . Third, the consortium's blood pressure analysis revealed that as little as five additional minutes of exercise-like activity per day is associated with measurable reductions in systolic and diastolic blood pressure, while clinically meaningful improvements can be achieved with 20 to 27 minutes of reallocation . Finally, the deleterious association of sitting time with cardiometabolic health becomes markedly worse above approximately 12 hours per day, reinforcing the threshold identified in the Columbia activity cocktail study covered in the previous monograph .

2. Consortium in Detail

Design and Structure

ProPASS is an international research collaboration platform, not a single study. It launched in 2017 with an initial focus on cohorts using thigh-worn accelerometry, and in mid-2023 expanded to include wrist-worn wearables . As of 2025, the consortium encompasses 41 cohorts across 24 countries, with a combined sample size exceeding 200,000 participants. The founding and flagship analyses drew on six core cohorts from five countries, including The Maastricht Study from the Netherlands, the 1970 British Birth Cohort Study from the United Kingdom, the Australian Longitudinal Study on Women's Health, the Danish Physical Activity Cohort With Objective Measurements, the Nijmegen Exercise Study from the Netherlands, and the Finnish Retirement and Aging Study . The consortium is coordinated by an international steering committee led by researchers from the University of Sydney, University College London, and collaborating institutions worldwide .

Methodology

ProPASS employs several methodological innovations that distinguish it from previous physical activity research:

· Thigh-worn accelerometry: Unlike wrist-worn consumer wearables that estimate activity based on arm movement, thigh-worn devices directly measure posture. They can distinguish sitting from standing from lying down, and they classify walking cadence, enabling researchers to differentiate slow walking from fast walking and from exercise-like activity such as running and cycling . This measurement precision allows ProPASS to analyze up to six distinct movement behaviors within the 24-hour day: sleep, sedentary behavior, standing, slow walking, fast walking, and exercise-like activity.

· Compositional data analysis: ProPASS uses a statistical framework called compositional analysis that treats the 24-hour day as a finite whole. Every minute reallocated to one behavior must come from another. This approach models what happens to health outcomes when a person replaces, for example, 30 minutes of sitting with 30 minutes of walking, providing the kind of behavioral substitution evidence that isolated analyses cannot produce .

· Individual participant data harmonization: The consortium developed standardized protocols to harmonize accelerometer data, covariate definitions, and health outcome measurements across different cohorts that used different devices and slightly different protocols, enabling pooled analysis of tens of thousands of participants .

· Isotemporal substitution modeling: This technique estimates the effect on a health outcome of replacing a fixed duration of one behavior with an equal duration of another behavior, while holding total time constant. This directly addresses the question of what individuals should do with the time they currently spend sitting or sleeping poorly .

Key Consortium Publications

The consortium's findings have been published in leading medical journals. The flagship 2023 publication in the European Heart Journal examined five-part movement compositions across 15,253 participants and established the hierarchy of behavior associations with cardiometabolic biomarkers . A 2024 paper in Circulation examined six-part compositions and blood pressure in 14,761 participants . A 2025 publication investigated the joint associations of sleep duration, regularity, and efficiency with cardiometabolic health in 14,085 participants . A further 2025 study examined the joint associations of sleep patterns and daily step count with cardiometabolic biomarkers .

3. Key Findings

A Hierarchy of Movement Behaviors for Cardiometabolic Health

The flagship analysis published in the European Heart Journal revealed a clear hierarchy of behaviors for cardiometabolic health . Moderate-to-vigorous physical activity demonstrated the strongest protective associations across all outcomes, including body mass index, waist circumference, HDL cholesterol, total-to-HDL cholesterol ratio, triglycerides, and glycated hemoglobin. Light physical activity was beneficial but less potent. Standing was beneficial when it replaced sitting. Sleep was associated with worse outcomes when it replaced physical activity and better outcomes when it replaced sitting, illustrating the importance of considering substitutions, not absolute durations.

Small Amounts of Exercise Produce Measurable Blood Pressure Reductions

The blood pressure analysis published in Circulation established that as little as five minutes of additional exercise-like activity per day is associated with a reduction of 0.68 mm Hg in systolic blood pressure and 0.54 mm Hg in diastolic blood pressure . Clinically meaningful improvements of 2 mm Hg in systolic blood pressure, which are associated with reduced cardiovascular events at the population level, could be estimated after replacing 20 to 27 minutes of sitting, standing, walking, or sleeping with additional exercise .

Sleep Regularity and Efficiency Rival Sleep Duration in Importance

The 2025 sleep-focused analysis challenged the common public health emphasis on sleep duration alone. Short sleep duration, irregular sleep patterns, and low sleep efficiency were each independently associated with worse cardiometabolic risk scores, with sleep irregularity showing the strongest association . In joint analyses, individuals with irregular and inefficient sleep had worse cardiometabolic profiles regardless of whether they slept a short, adequate, or long duration. The combination of all three risk factors—short, irregular, and inefficient sleep—produced the worst cardiometabolic profiles .

Physical Activity Partially Offsets Poor Sleep, But Heightens Risk When Absent

The analysis of sleep patterns and step count demonstrated that the combination of irregular or insufficient sleep with low daily steps produced the least favorable cardiometabolic health profiles . Short sleep combined with low step count was associated with a higher BMI and waist circumference than either factor alone, suggesting that physical activity and sleep interact in ways that amplify risk when both are poor .

Sitting Beyond 12 Hours Is Especially Harmful

The dose-response analysis of sitting time found that the adverse association between sitting and cardiometabolic health became markedly more unfavorable when daily sitting exceeded approximately 12.1 hours . This finding provided an objective, device-based threshold that closely aligns with the 11-to-12-hour threshold identified in the Columbia activity cocktail study explored in the previous monograph.

4. Lessons Learnt

Movement behaviors are not independent lifestyle choices.

The most fundamental lesson from ProPASS is that physical activity, sedentary behavior, and sleep are mathematically and physiologically interdependent. Studying them in isolation produces an incomplete picture of health determinants. Increasing exercise necessarily reduces time available for something else in the 24-hour day, and what that something else is determines the net health effect. This interdependence must be reflected in research design, clinical counseling, and public health guidelines .

Device-based measurement reveals patterns invisible to self-report.

The use of thigh-worn accelerometry across all ProPASS cohorts allowed the consortium to measure posture and movement types with a precision that self-reported questionnaires cannot match. The ability to distinguish sitting from standing, slow walking from fast walking, and sleep from sedentary time while awake generated findings that would have been impossible using traditional survey methods. The transition from self-reported to device-based evidence is essential for the next generation of physical activity guidelines .

Quality of sleep matters alongside quantity.

ProPASS findings elevate sleep regularity and sleep efficiency to equal importance with sleep duration for cardiometabolic health . Public health messaging that focuses exclusively on getting seven to eight hours of sleep per night may miss critical dimensions of sleep health. Going to bed and waking at consistent times and achieving efficient, uninterrupted sleep may be as important as total hours slept.

Minimal exercise doses have measurable benefits.

The finding that five additional minutes of exercise-like activity is associated with lower blood pressure provides an evidence-based entry point for individuals who find current exercise guidelines daunting . These small, feasible additions to daily life, which the consortium and related researchers have described as exercise snacks, represent a pragmatic public health approach that complements the traditional emphasis on 150 minutes per week.

Global collaboration is necessary for device-based guidelines.

ProPASS demonstrates that no single cohort, however well designed, can provide the scale, diversity, and methodological rigor needed to inform population-level physical activity guidelines based on device-measured behavior. The consortium model, combining harmonized data from dozens of cohorts across countries and continents, represents the future of physical activity epidemiology.

5. How This Research Can Help Humanity

Informing the Next Generation of Physical Activity Guidelines

The World Health Organization and national health agencies currently base physical activity guidelines primarily on self-reported data, which is subject to recall bias and cannot capture the full 24-hour composition. ProPASS is explicitly designed to provide the device-based evidence that will underpin future guidelines, enabling recommendations that address not only how much to exercise but how to structure the entire day, including sitting, standing, light activity, and sleep .

Providing Evidence for the Movement Cocktail Approach

ProPASS findings directly validate and extend the movement cocktail concept introduced in the Columbia activity cocktail study. The compositional analyses show that multiple different combinations of activities can yield equivalent health benefits, giving individuals flexibility to choose the pattern that fits their life, preferences, and constraints. This is a fundamentally empowering message: health is achievable through different daily movement profiles, not just one prescribed regimen.

Quantifying Minimal Effective Doses

The identification of minimal time displacements for measurable health benefit, ranging from 3.8 minutes for glycated hemoglobin improvement to 12.7 minutes for triglyceride reduction, provides specific, achievable targets for behavior change . These minimal doses are far below current guideline thresholds and offer an evidence-based starting point for the most inactive individuals.

Elevating Sleep Within the Movement Framework

By formally incorporating sleep into the 24-hour composition, ProPASS elevates sleep from a separate health domain to an integral component of daily movement behavior. The finding that sleep irregularity and inefficiency predict cardiometabolic risk independently of duration has implications for how sleep health is discussed in clinical encounters and public health campaigns .

Building Infrastructure for Global Health Research

The consortium's expansion from six initial cohorts to 41 cohorts across 24 countries, and from thigh-worn to wrist-worn wearables, creates a research infrastructure with the scale and diversity to investigate how movement behaviors affect health across different populations, cultures, and disease contexts . This infrastructure will support research for years to come.

6. Final Summary

Most Important Takeaways

1. The 24-hour composition concept is essential, not optional.

ProPASS has demonstrated empirically that physical activity, sitting, standing, and sleep are mathematically interdependent behaviors that must be analyzed and understood together. No single behavior can be prescribed in isolation without considering what it will displace in the finite 24-hour day .

2. Moderate-to-vigorous activity is the most time-efficient health investment.

Across all ProPASS analyses, moderate-to-vigorous physical activity consistently demonstrates the strongest protective associations with cardiometabolic outcomes per unit of time. Reallocating time from any other waking or sleeping behavior into MVPA yields health benefits, though the magnitude depends on the displaced behavior .

3. Small changes yield measurable benefits.

Five additional minutes of exercise-like activity is associated with lower blood pressure. Ten to 15 minutes of reallocation can produce clinically meaningful diastolic blood pressure improvements. These small, achievable targets make health protection accessible to individuals who cannot meet traditional exercise guidelines .

4. Sleep quality and regularity rival sleep quantity.

Sleep irregularity and poor sleep efficiency are associated with worse cardiometabolic health even when total sleep duration is adequate. Individuals with all three risk factors—short, irregular, and inefficient sleep—have the worst cardiometabolic profiles, while those with adequate, regular, and efficient sleep are best protected .

5. The worst health profiles emerge when multiple behaviors are suboptimal.

The joint analyses of sleep and physical activity demonstrate that the combination of irregular or insufficient sleep with low physical activity produces the most adverse cardiometabolic profiles. This finding supports a holistic approach to lifestyle health in which multiple behaviors are addressed simultaneously .

Action Points

For Individuals:

· Think compositionally: When planning physical activity, consider what you will do less of to make time. Replacing sitting with movement yields the greatest benefit. Replacing sleep with exercise may partially or fully offset the exercise benefit.

· Prioritize short exercise bursts: The finding that five minutes of exercise-like activity lowers blood pressure means that brief stair climbs, brisk walks, or short runs distributed throughout the day have measurable health value. Accumulating these exercise snacks is a legitimate strategy for those who cannot sustain longer sessions.

· Attend to sleep regularity: Going to bed and waking at consistent times, even on weekends, may protect cardiometabolic health independently of how many hours you sleep. Improving sleep efficiency, by minimizing nighttime awakenings, is equally important.

· Keep sitting below 12 hours: The dose-response data indicate that sitting beyond approximately 12 hours per day is associated with markedly worse cardiometabolic profiles. If your occupation requires prolonged sitting, intentional breaks and active commuting become even more critical.

For Clinicians:

· Counsel on behavior substitution, not just exercise addition: Ask patients what activity a new exercise routine will replace. Help them identify sitting time to swap for movement rather than encouraging exercise that comes at the expense of sleep.

· Assess sleep quality, not just duration: Inquire about sleep regularity and whether patients wake feeling rested. Irregular sleep patterns and poor sleep efficiency are independently associated with cardiometabolic risk and may be more modifiable through behavioral intervention than sleep duration .

· Prescribe minimal effective doses for inactive patients: For patients who are completely sedentary, frame five to ten minutes of daily exercise-like activity as a meaningful health intervention supported by device-based evidence, rather than presenting 150 minutes per week as the only target.

For Public Health Authorities:

· Move toward device-based guidelines: The evidence generated by ProPASS supports a transition from self-reported exercise guidelines to device-informed 24-hour movement guidelines that address sitting, standing, light activity, exercise, and sleep as an integrated whole.

· Emphasize sleep regularity in public messaging: Public health campaigns about sleep have focused almost exclusively on duration. ProPASS findings justify adding messaging about consistent sleep-wake timing and sleep quality.

· Recognize minimal-dose exercise in official recommendations: Acknowledge that exercise volumes below current guideline thresholds confer measurable health benefits, to reduce the all-or-nothing perception that discourages completely inactive individuals.

For Researchers:

· Expand to longitudinal and interventional designs: The current ProPASS evidence is primarily cross-sectional. Longitudinal analyses examining how changes in movement composition over time predict changes in health outcomes, and intervention trials testing whether prescribing specific behavior substitutions improves cardiometabolic biomarkers, are the next priorities.

· Investigate mechanisms: The observational associations identified by ProPASS require mechanistic explanation. Research examining how different movement compositions affect inflammatory markers, autonomic function, insulin sensitivity, and adipose tissue biology is needed.

· Include under-represented populations: The consortium's expansion to 41 cohorts across 24 countries provides an opportunity to examine whether movement-health associations differ across ethnicities, socioeconomic strata, and geographic regions, informing whether population-specific guidelines are warranted .

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Recommended Follow-Up Study

The 24-Hour Movement Intervention Trial with Compositional Prescribing

The ProPASS evidence base identifies the optimal movement compositions associated with cardiometabolic health, but this evidence is primarily cross-sectional and observational. The critical next step is a multi-arm randomized controlled trial that tests whether prescribing specific behavior substitutions produces the cardiometabolic improvements predicted by the compositional models. Participants would be randomized to one of several arms: substituting 30 minutes of sitting with moderate-to-vigorous activity; substituting 30 minutes of sitting with light activity and standing; a sleep regularity intervention targeting consistent bed and wake times; or a control condition. Outcomes would include the cardiometabolic biomarkers examined in ProPASS publications, measured at baseline, six months, and twelve months, with adherence verified by thigh-worn accelerometry. Such a trial would establish whether the associations identified by ProPASS reflect causal relationships and would provide the strongest possible evidence to inform clinical and public health recommendations.

List of Other Related / Connected Studies and Research

The Columbia Activity Cocktail Study

The study covered in the previous monograph in this series, demonstrating that 30 minutes of exercise provides no mortality benefit for individuals sitting more than 11 to 12 hours daily and identifying multiple movement combinations that equivalently reduce mortality risk. ProPASS and the Columbia study share the compositional framework and produce converging evidence on the 12-hour sitting threshold and the hierarchy of movement behaviors .

The WHO 2020 Physical Activity and Sedentary Behavior Guidelines

The World Health Organization's updated guidelines incorporated, for the first time, explicit recommendations to limit sedentary time alongside the traditional exercise prescription. ProPASS provides the device-based evidence that supports and extends these guidelines toward specific behavior substitution recommendations.

The UK Biobank Accelerometer Sub-Study

A large-scale resource of wrist-worn accelerometer data in approximately 100,000 participants. While the UK Biobank uses wrist rather than thigh wearables, its scale and linkage to health outcomes make it a complementary resource. ProPASS has expanded to include wrist-worn studies, enabling methodological harmonization between the two device types .

The MATADOR Study

The intermittent energy restriction study covered in an earlier monograph in this series. MATADOR and ProPASS share a conceptual geneology: both challenge linear, dose-based models of health behavior and demonstrate that how a behavior is structured across time, whether dieting or daily movement, matters as much as the total amount.

The International Study of Movement Behaviors in Early Childhood

An analogue to ProPASS focused on children under five years, examining the composition of physical activity, sedentary behavior, and sleep in early life. Together with ProPASS, this work extends the compositional framework across the lifespan.

The Epithelial Barrier Hypothesis

Connecting conceptually to the broader theme explored throughout this monograph series, the idea that modern environments disrupt biological systems that evolved to expect certain inputs. ProPASS extends this theme to the movement environment, demonstrating that modern patterns of prolonged sitting and insufficient movement represent a mismatch with the physical activity levels that shaped human physiology.