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Public health guidelines on physical activity (PA) establish national policy agendas and provide the basis for setting goals and targets. Advances in measurement and resulting new scientific findings lead to evolution of PA guidelines. PA surveillance serves to track compliance with national guidelines, usually expressed as the proportion of the population ‘meeting’ the main quantitative guidelines. The WHO recently completed a process to review and update the global PA guidelines. Changes to the guidelines, such as removal of a 10-min bout criterion, pose challenges for PA surveillance. We review the evolution of PA guidelines and associated surveillance methods and explore implications of the updated guidelines for changes in population surveillance and opportunities for technological approaches to PA to enhance surveillance.

To implement effective non-communicable disease prevention programmes, policy makers need data for physical activity levels and trends. In this report, we describe physical activity levels worldwide with data for adults (15 years or older) from 122 countries and for adolescents (13–15-years-old) from 105 countries. Worldwide, 31·1% (95% CI 30·9–31·2) of adults are physically inactive, with proportions ranging from 17·0% (16·8–17·2) in southeast Asia to about 43% in the Americas and the eastern Mediterranean. Inactivity rises with age, is higher in women than in men, and is increased in high-income countries. The proportion of 13–15-year-olds doing fewer than 60 min of physical activity of moderate to vigorous intensity per day is 80·3% (80·1–80·5); boys are more active than are girls. Continued improvement in monitoring of physical activity would help to guide development of policies and programmes to increase activity levels and to reduce the burden of non-communicable diseases.

ObjectiveTo compare the country-level absolute and relative contributions of physical activity at work and in the household, for travel, and during leisure-time to total moderate-to-vigorous physical activity (MVPA).MethodsWe used data collected between 2002 and 2019 from 327 789 participants across 104 countries and territories (n=24 low, n=34 lower-middle, n=30 upper-middle, n=16 high-income) from all six World Health Organization (WHO) regions. We calculated mean min/week of work/household, travel and leisure MVPA and compared their relative contributions to total MVPA using Global Physical Activity Questionnaire data. We compared patterns by country, sex and age group (25–44 and 45–64 years).ResultsMean MVPA in work/household, travel and leisure domains across the 104 countries was 950 (IQR 618–1198), 327 (190–405) and 104 (51–131) min/week, respectively. Corresponding relative contributions to total MVPA were 52% (IQR 44%–63%), 36% (25%–45%) and 12% (4%–15%), respectively. Work/household was the highest contributor in 80 countries; travel in 23; leisure in just one. In both absolute and relative terms, low-income countries tended to show higher work/household (1233 min/week, 57%) and lower leisure MVPA levels (72 min/week, 4%). Travel MVPA duration was higher in low-income countries but there was no obvious pattern in the relative contributions. Women tended to have relatively less work/household and more travel MVPA; age groups were generally similar.ConclusionIn the largest domain-specific physical activity study to date, we found considerable country-level variation in how MVPA is accumulated. Such information is essential to inform national and global policy and future investments to provide opportunities to be active, accounting for country context.

Land-use and transport policies contribute to worldwide epidemics of injuries and non-communicable diseases through traffic exposure, noise, air pollution, social isolation, low physical activity, and sedentary behaviours. Motorised transport is a major cause of the greenhouse gas emissions that are threatening human health. Urban and transport planning and urban design policies in many cities do not reflect the accumulating evidence that, if policies would take health effects into account, they could benefit a wide range of common health problems. Enhanced research translation to increase the influence of health research on urban and transport planning decisions could address many global health problems. This paper illustrates the potential for such change by presenting conceptual models and case studies of research translation applied to urban and transport planning and urban design. The primary recommendation of this paper is for cities to actively pursue compact and mixed-use urban designs that encourage a transport modal shift away from private motor vehicles towards walking, cycling, and public transport. This Series concludes by urging a systematic approach to city design to enhance health and sustainability through active transport and a move towards new urban mobility. Such an approach promises to be a powerful strategy for improvements in population health on a permanent basis.

On the eve of the 2012 summer Olympic Games, the first Lancet Series on physical activity established that physical inactivity was a global pandemic, and global public health action was urgently needed. The present paper summarises progress on the topics covered in the first Series. In the past 4 years, more countries have been monitoring the prevalence of physical inactivity, although evidence of any improvements in prevalence is still scarce. According to emerging evidence on brain health, physical inactivity accounts for about 3·8% of cases of dementia worldwide. An increase in research on the correlates of physical activity in low-income and middle-income countries (LMICs) is providing a better evidence base for development of context-relevant interventions. A finding specific to LMICs was that physical inactivity was higher in urban (vs rural) residents, which is a cause for concern because of the global trends toward urbanisation. A small but increasing number of intervention studies from LMICs provide initial evidence that community-based interventions can be effective. Although about 80% of countries reported having national physical activity policies or plans, such policies were operational in only about 56% of countries. There are important barriers to policy implementation that must be overcome before progress in increasing physical activity can be expected. Despite signs of progress, efforts to improve physical activity surveillance, research, capacity for intervention, and policy implementation are needed, especially among LMICs.

Self-reported rates of participation in sport vary by country. In the UK, about 40% of men and women aged 16 years or older participate in at least one sport every week. Although few data exist to assess trends for participation in sport, there is little evidence of change in the past decade among adults. Large cohort studies suggest that such participation in sport is associated with a 20–40% reduction in all-cause mortality compared with non-participation. Randomised trials and crossover clinical studies suggest that playing sport is associated with specific health benefits. Some sports have relatively high injury risk although neuromuscular training programmes can prevent various lower extremity injuries. Clinicians can influence a large number of patients through brief interventions that promote physical activity, and encouragement toward participation in sport for some physically inactive patients qualifies as evidence-based therapy. Exercise might also be considered as a fifth vital sign and should be recorded in patients' electronic medical records and routine histories.

Correspondence to Professor Emmanuel Stamatakis, School of Health Sciences, University of Sydney, Sydney, NSW 2006, Australia; emmanuel.stamatakis@sydney.edu.au This special issue of BJSM celebrates the launch of the new 2020 WHO Global guidelines on physical activity and sedentary behaviour, an effort that took over 18 months and involved over 40 scientists and international collaboration across six continents.1 WHO guidelines reflect a consensus on the latest science on the health impacts of physical activity and sedentary behaviour across the age spectrum and, for the first time, cover important—but previously underserved—population groups: people who live with chronic disease or disabilities, and pregnant and postpartum women. The implications for national monitoring of trends in population levels of physical activity is addressed by Troiano et al 4 who kick off with a challenging discussion acknowledging that long term health surveillance thrives on consistency and stability—which often contrasts with the needs to reflect changing science and guidelines evolution. In their analysis of physical activity levels, the authors unpick for the first time at scale, the global domain-specific picture of the relative contribution of work, household, travel and leisure physical activity to national population levels of physical activity across 104 countries from six WHO regions.6 This provides an invaluable insight into where more investments and action on promoting physical activity should focus and a stimulus to global health researchers. Disseminating the new guidelines effectively can accelerate implementation of the policy recommendations in the WHO’s Global Action Plan on Physical Activity 2018–2030 and its ambitious target of 15% improvement by 2030.11 This catalytic effect can be enhanced by the impacts of the COVID-19 pandemic which is rapidly transforming the world around us. Besides the magnitude of tragic consequences, the pandemic has opened unexpected opportunities to position and prioritise physical activity in the transportation12 and health13 agendas of governments around the world.

ObjectivesTo describe new WHO 2020 guidelines on physical activity and sedentary behaviour.MethodsThe guidelines were developed in accordance with WHO protocols. An expert Guideline Development Group reviewed evidence to assess associations between physical activity and sedentary behaviour for an agreed set of health outcomes and population groups. The assessment used and systematically updated recent relevant systematic reviews; new primary reviews addressed additional health outcomes or subpopulations.ResultsThe new guidelines address children, adolescents, adults, older adults and include new specific recommendations for pregnant and postpartum women and people living with chronic conditions or disability. All adults should undertake 150–300 min of moderate-intensity, or 75–150 min of vigorous-intensity physical activity, or some equivalent combination of moderate-intensity and vigorous-intensity aerobic physical activity, per week. Among children and adolescents, an average of 60 min/day of moderate-to-vigorous intensity aerobic physical activity across the week provides health benefits. The guidelines recommend regular muscle-strengthening activity for all age groups. Additionally, reducing sedentary behaviours is recommended across all age groups and abilities, although evidence was insufficient to quantify a sedentary behaviour threshold.ConclusionThese 2020 WHO guidelines update previous WHO recommendations released in 2010. They reaffirm messages that some physical activity is better than none, that more physical activity is better for optimal health outcomes and provide a new recommendation on reducing sedentary behaviours. These guidelines highlight the importance of regularly undertaking both aerobic and muscle strengthening activities and for the first time, there are specific recommendations for specific populations including for pregnant and postpartum women and people living with chronic conditions or disability. These guidelines should be used to inform national health policies aligned with the WHO Global Action Plan on Physical Activity 2018–2030 and to strengthen surveillance systems that track progress towards national and global targets.

Hosts, organisers, and sports’ governing bodies should ensure that everyone reaps health benefits

Objective The ‘single-item measure’ was developed as a short self-report tool for assessing physical activity. The aim of this study was to test the criterion validity of the single-item measure against accelerometry. Design Participants (n=66, 65% female, age: 39±11 years) wore an accelerometer (ActiGraph GT3X) over a 7-day period and on day 8, completed the single-item measure. The number of days of ≥30 min of accelerometer-determined moderate to vigorous intensity physical activity (MVPA) were calculated using two approaches; first by including all minutes of MVPA and second by including only MVPA accumulated in bouts of ≥10 min (counts/min ≥1952). Associations between the single-item measure and accelerometer were examined using Spearman correlations and 95% limits of agreement. Percent agreement and κ statistic were used to assess agreement between the tools in classifying participants as sufficiently/insufficiently active. Results Correlations between the number of days of ≥30 min MVPA recorded by the single-item and accelerometer ranged from 0.46 to 0.57. Participants underreported their activity on the single-item measure (−1.59 days) when compared with all objectively measured MVPA, but stronger congruence was observed when compared with MVPA accumulated in bouts of ≥10 min (0.38 days). Overall agreement between the single-item and accelerometry in classifying participants as sufficiently/insufficiently active was 58% (k=0.23, 95% CI 0.05 to 0.41) when including all MVPA and 76% (k=0.39, 95% CI 0.14 to 0.64) when including activity undertaken in bouts of ≥10 min. Conclusions The single-item measure is a valid screening tool to determine whether respondents are sufficiently active to benefit their health.