World Health Organization 2020 guidelines on physical activity and sedentary behaviour

The updated WHO 2020 Guidelines on Physical Activity and Sedentary Behaviour provide clear, evidence-based, recommendations on how much physical activity provides health benefits for different population groups and on the potential risks of sedentary behaviours. These guidelines should be used to inform global, regional and national policy actions and investment, as well as to guide and strengthen national health behaviour surveillance systems that track progress towards national and global targets. The development of these new guidelines identified important areas requiring further research and thus also identified research priorities for the academic and research community.

What remains the same?

The evidence confirms the value of participating in regular physical activity to achieve health benefits across all ages and abilities. Further it supports key messages that some physical activity is better than none and that more is better for optimal health outcomes. More specifically, the evidence reaffirms all adults should undertake regular physical activity and should aim to achieve at least 150 min of moderate-intensity, or 75 min of vigorous-intensity aerobic physical activity per week, or some equivalent combination of moderate-intensity and vigorous-intensity aerobic physical activity. Among children and adolescents, an average of 60 min/day of moderate-to-vigorous intensity physical activity across the week (most of which should be aerobic), leads to health benefits. Furthermore, the guidelines continue to reinforce the value of muscle-strengthening activity for all adults and children. The key physical activity-specific recommendations above remain largely unchanged from 2010 and are consistent with other recently developed physical activity guidelines from several countries.13 17–22

What is new?

There are a few important differences in the new guidelines that should be highlighted for each age group. First, in adults, the previous stipulation that physical activity should be accumulated in at least 10 min bouts has been removed. This change reflects the accumulated evidence from cohort studies, which shows physical activity of any bout duration is associated with improved health outcomes, including all-cause mortality.16 23 Second, these updated guidelines for adults now specify a target range of 150–300 min of moderate-intensity and 75–150 min of vigorous-intensity physical activity, compared with the previous guidelines that focused on achieving at least 150 min of moderate-intensity or 75 min of vigorous-intensity activity per week. This change acknowledges that there is a range of physical activity which captures the maximal risk reductions for health outcomes associated with physical activity and going beyond this range does not appreciably further decrease the risk of major outcomes such as all-cause or CVD mortality. Third, with respect to older adults, the recommendation regarding multicomponent physical activity that emphasises functional balance and strength training to enhance functional capacity and prevent falls now applies to all older adults rather than specifically those with poor mobility. This change acknowledges the large volume of evidence demonstrating unequivocal beneficial effects of this physical activity type on the functional capacity and risk of falls in older people with a range of functional abilities.

There was also one key change in the new recommendations for children and adolescents. Specifically, the updated recommendation is now to do at least an ‘average of 60 min/day’ of MVPA rather than the previously stated ‘accumulate 60 min of physical activity daily’. Although this might appear to be a subtle difference, the change better reflects the scientific evidence as most studies reported associations between an average daily value of physical activity rather than an accumulation of 60 min on each and every day of the week.

The new recommendation that sedentary behaviour should be limited across all groups is an important addition to these new global guidelines since 2010 and is in line with other recent country-level guidelines19 20 that generally support the notion of moving more and reducing sedentary time (‘sitting less’ for ambulatory people). Although specifying a quantitative threshold on the amount of sedentary behaviour was strongly considered, there was insufficient evidence. Furthermore, variations in how sedentary time was measured, and that a threshold would likely vary by health outcome, by level of physical activity and by population subgroups, made quantifying upper time limits difficult to ascertain.

The recommendation to limit sedentary behaviour was qualified with an acknowledgement that replacing sedentary time with any intensity of physical activity (including light intensity) has health benefits. This recommendation was based first on the juxtaposed evidence of lower levels of time spent in sedentary behaviours being beneficial for health even among those with modest levels of MVPA, and on the emerging, largely cross-sectional evidence, from ‘replacement’ studies (ie, isotemporal substitution) demonstrating these effects more directly. Second, there was evidence of effect modification between sedentary time and MVPA, which supported the development of a second recommendation emphasising the benefits of undertaking more than the recommended levels of MVPA to help reduce the detrimental effects of high levels of sedentary behaviour. The important practical application of this recommendation is to encourage the promotion of multiple approaches to limiting the negative health outcomes associated with high levels of sedentary time. This includes recommending individuals reduce their time spent in sedentary behaviours or increase their MVPA to help offset the negative impact, or some combination of both strategies. Given that time spent in sedentary behaviours at work, for transport or for recreation appears to be overtaking time spent in more healthy physical activity behaviours during waking hours, the GDG deemed it important to attend to both physical activity and sedentary time and, therefore, to recommend a ‘balance’ of these behaviours for better health. Although the evidence on health benefits of ‘breaking up’ sedentary time and types of sedentary behaviours was reviewed, the GDG considered that there was insufficient evidence to provide specific quantified recommendations.

An additional issue related to the sedentary recommendations was the decision to opt specifically for the use of the term ‘sedentary behaviour’ instead of ’sitting’, which has been commonly used in several national guidelines. This wording choice was deliberate and made to reflect the overarching agenda of these new guidelines to be inclusive of people living with disability and therefore to emphasise options for reducing sedentary behaviour among wheelchair users and those with low mobility, where prolonged sitting may be unavoidable. For such people, sedentary time can be minimised through physical activity while remaining seated.

Guidelines for special groups—key considerations

The development of recommendations on physical activity and sedentary behaviours specifically for key populations, namely, people living with disability and chronic conditions, as well as for pregnant and postpartum women, addressed important gaps in global health policy. These new recommendations affirm that physical activity is feasible for these groups; and provides for the first-time global science-based recommendations to inform the development of population-based initiatives to improve health outcomes for these population groups. In particular, these recommendations for people living with chronic disease and disability should stimulate increased attention in policy, surveillance, investment and research aligned to the agenda of inclusion as called for in the sustainable development goals as well as in the convention on the rights of people living with disability.

In undertaking this new work there were however several limitations. Specifically, the association between physical activity and health outcomes was only reviewed for selected chronic conditions and disabilities and there was limited evidence to inform on the optimal type, frequency or duration of activity by health condition. Due to the lack of direct evidence, considerable extrapolation was needed to develop the recommendations on physical activity and the recommendations on sedentary behaviour relied entirely on the evidence from the general population. Nonetheless, the GDG concluded the strong recommendations for this population reflect the balance between desirable and undesirable consequences and send an important message to support the inclusion of people living with disability in physical activity population health initiatives.

Using these guidelines

Developing global guidelines is not an end in itself. The 2020 WHO guidelines provide a set of evidence-based physical activity and sedentary behaviour recommendations that national governments can adopt, thus removing the need for countries to use limited resources to undertake their own scientific reviews and expert consensus process. This issue is particularly important for LMICs where resources may be limited. During adoption of these global guidelines, national policymakers are encouraged to consider their national context and factors such as culture, ethnic diversity, existing social norms and the current provision for physical activity promotion within healthcare services as well as primary prevention, to inform adaptations and dissemination of the guidelines.

The existence of guidelines, in isolation, is unlikely to lead to increases in population levels of physical activity. It is critical that they are supported by coordinated dissemination to key audiences and a sustained national public education communication strategy. Furthermore, communication activities must be combined with implementation of setting specific policy actions to support behaviour change. How to optimise the impact of physical activity guidelines through effective communication strategies is explored in a separate paper in this issue.

In 2018, the new GAPPA 2018–2030 set a target to reduce physical inactivity by 15% by 2030 and outlined 20 recommended policy actions and interventions. These included recommending all countries combine sustained national public education and awareness campaigns with the integration of physical activity counselling programmes into primary and secondary healthcare. Other recommendations included the creation of appropriate and supportive environments for physical activity for all population groups and increasing opportunities for physical activity in schools, workplaces, cities and communities and as a form of safe and sustainable transport.

These 2020 global guidelines provide focus to the overall goal of national policy and support expanding the scope of actions to include additional groups, such as people living with disability, chronic conditions and women who are pregnant or post partum. National policy will need to offer a route to the development of appropriate programme delivery and practice that recognises community needs and the diversity of groups and contexts and seeks to reduce existing disparities in access to and engagement in physical activity. The inclusion of global recommendations on muscle strengthening activities is not new in these updated guidelines, but the GDG implicitly recognised their increasing importance due to an expanding evidence base. Promotion of muscle strengthening and falls prevention activities have been largely forgotten or ignored in the past27 28 and in most countries a much greater focus on this is now required for policy and practice.

Implications of these guidelines for health surveillance

These updated guidelines have several implications for future population monitoring and research. First, currently used surveillance instruments and/or protocols will need adaptation to align with the key changes made in these updated guidelines. Second, national population surveillance systems will need to be extended to include and track trends in key populations such as children aged 5–10 years, pregnant and postpartum women, older adults and persons living with disability or chronic conditions. Third, monitoring systems should be strengthened to track trends in muscle-strengthening exercises, which are of increasing importance with an ageing demographic in many countries. Fourth, as many countries are reliant on self-reported methods, which have well-established limitations, there is a need to accelerate advancements in sensor technology to ensure it provides a practical and affordable approach to assessing physical activity and sedentary behaviours. The potential of the new guidelines for advancing surveillance as well as the need for development of device-based approaches to inform a new generation of guidelines is discussed by Troiano et al.

Key knowledge gaps

Despite the large quantity of data relating physical activity, and increasingly sedentary behaviours, to health outcomes across the life-span, the GDG discussions revealed important evidence gaps, which should be prioritised to inform future guidelines. The most common need cited is more research on the dose-response relationship between volume and/or intensity of physical activity and health outcomes. Such information is key to establishing minimal effective doses and maximum safety thresholds of physical activity for different population subgroups. There also remains limited evidence from LMICs and economically disadvantaged or underserved communities and many studies are not designed or powered to test for effect modification by various sociodemographic factors. Such information is important for making more specific public health recommendations and reducing health disparities in more vulnerable sectors of the population. Further details on the research gaps arising from these new guidelines can also be found elsewhere.