In accordance with the GRADE process, the proposed wording of the updated recommendations, and the rating of their strength (“strong” or “conditional”), were based on consideration of the balance of benefits to harms; the certainty of evidence; sensitivity to the values and preferences of those affected by the guidelines; the potential impact on gender, social and health equity; and acceptability, feasibility and resource implications. These were considered for each population group, but given the similarity of issues and considerations discussed, are consolidated and presented here.
The strength of the recommendation was primarily based on the assessed balance of benefits to harms. Recommendations were graded “strong” if the balance of benefits to harms was assessed as substantial for the target population for the recommendation, and “conditional” if the balance of benefits to harms was small or there was important likely variability in benefits in the target population. The evidence on harms was specifically sought through the commissioning of a new systematic review. However, this was limited, as most evidence focuses on injuries and harms to elite and competitive athletes, rather than the general population. Overall, despite the limited evidence, and informed by expert opinion, it was concluded that the risk was no greater than small. The evidence generally indicated that the benefits of physical activity far outweighed the harms, and that physical activity can be an important intervention to support closing an existing health gap, particularly for disadvantaged populations.
Issues of health equity, feasibility and acceptability were also considered by the GDG and formed part of the online public consultation on the draft recommendations held between 31 March 2020 and 17 April 2020. The survey for the public consultation asked specific questions on the balance between the costs to individuals and governments of implementing the recommendations, and the potential health benefits, and whether the guidelines would improve health equity. In addition, the draft recommendations and the feedback form were sent to countries that had recently expressed an interest in developing, or had initiated the process of drafting, national guidelines on physical activity. Feedback was received from more than 420 submissions to the online consultation, and additional collation of feedback from the WHO European Regional Office, incorporating comments from WHO Collaborating Centres and Member States. The feedback from this consultation was collated, reviewed by the GDG, and used to further inform the consideration on feasibility, resource implications, and health equity through consultation with the Steering Group and the GDG.
Decisions were reached by consensus through discussion. The GDG came to consensus on each recommendation and on the strength of the recommendation; ratings and voting were not required.
ASSESSMENT OF THE CERTAINTY OF EVIDENCE
The GRADE framework was used by the GDG to examine the certainty of primary research contributing to each outcome identified in the PI/ECOs, and assessed the overall certainty of evidence taking into consideration the risk of bias, inconsistency, imprecision, indirectness of the evidence and publication bias across each outcome. GRADE tables detailing this information for each PI/ECO are available in the Web Annex: Evidence profiles. The assessment of the certainty of the evidence was based on an overall assessment across all evaluated outcomes and prioritized all-cause mortality and cardiovascular mortality as the most critical outcomes, followed by other clinical outcomes (falls, depression, cognition, health-related quality of life, etc), then intermediate outcomes (e.g. cardiometabolic markers, other metabolic markers), as well as harms. Where the evidence had not been specifically reviewed, such as for sedentary behaviour in subpopulations primarily due to a lack of evidence for these groups, the evidence for the general population was extrapolated and downgraded where this was deemed appropriate, due to indirectness.
BENEFITS AND HARMS
The development of the recommendations included an assessment of adverse impacts or risks. Where there was limited evidence, decisions were based on the expertise of the GDG. Overall, for all populations it was concluded that the benefits of physical activity and limiting sedentary behaviour outweighed the potential harms. These guidelines are for the general population and do not address the benefits and harms experienced by athletes undertaking the types and amounts of activity necessary to improve performance-related fitness for participation in competition.
Doing some physical activity is better than doing none. If individuals are not currently meeting these recommendations, doing some physical activity will bring benefits to their health. They should start by doing small amounts of physical activity, gradually increasing frequency, intensity and duration over time. Pre-exercise medical clearance is generally unnecessary. Inactive individuals who gradually progress to undertaking moderate-intensity activity have no known risk of sudden cardiac events and very low risk of bone, muscle, or joint injuries. An individual who is habitually engaging in moderate-intensity activity can gradually increase to vigorous-intensity without needing to consult a health-care provider. Those who develop new symptoms when increasing their levels of activity should consult a health-care provider.
The choice of appropriate types and amounts of physical activity can be affected by pregnancy, chronic conditions, and disability, and should be undertaken as able and without contraindication. These individuals may wish to consult with a physical activity specialist or health-care professional for advice on the types and amounts of activity appropriate for their individual needs, abilities, functional limitations/complications, medications, and overall treatment plan. Light- and moderate-intensity physical activity are generally low risk and are recommended for all.
VALUES AND PREFERENCES
The values and preferences of those affected by the guidelines (in this case parents and caregivers, children and adolescents, adults, older adults, pregnant and postpartum women, people living with chronic conditions and/or disability) were considered. Overall it was concluded that there was little or no uncertainty about preferences regarding the main outcomes, including mortality and cardiovascular mortality. The estimated potential benefits greatly outweighed any potential harms, and as such, the GDG considered the recommendations to be not preference-sensitive.
RESOURCE IMPLICATIONS
The expert opinion of the GDG, and a small body of evidence reporting on economic analyses of interventions and savings to the health-care systems from increasing levels of physical activity, informed discussion on the resource implications of the recommendations in different settings. In addition, results from the online public consultation showed that over 75% of respondents agreed, or strongly agreed, that the benefits of implementing the guidelines would outweigh the cost to the individual, and 81% agreed, or strongly agreed, that the benefits of implementing the guidelines would outweigh the cost to government.
Available evidence and expert opinion recognize that substantial health benefits can be achieved at low risk through activities such as walking, that require no specific equipment or cost to the individual. Further, it was acknowledged that other forms of physical activities, for example structured sports, cycling and exercise classes, may incur costs, which can be a barrier for some individuals, particularly those with lower incomes. Government implementation of policy and programmes to promote and enable physical activity also requires investments in areas such as human resources, policy development, provision of facilities and services and potentially, equipment, some of which is incurred by ministries of health, but also in sectors outside of health, such as sport, education, transport and urban planning. The resources required may be at more than one level of government (national, subnational and local levels) to ensure all communities have equal access to physical activity opportunities.
These investments may involve new resources, but also can be addressed by reallocation of existing budgets to reflect the prioritization of facilities and programmes towards increasing population levels of physical activity. Examples of budget reallocation include towards infrastructure for walking and cycling from the existing transport budget, and towards “sports for all” from the sports budgets. In key settings, such as schools and workplaces, low-cost interventions, combined with changes to the physical environment, can support participation in physical activity and would also contribute to reducing inequities in opportunities to be active, experienced by some subpopulation groups. Overall, it was assessed that while there are resource implications to achieve these draft recommendations, implementation of actions is possible within current governance structures.
Further, evidence supports that substantial health savings are possible for the health-care system resulting from increasing levels of physical activity. In 2013 the global annual cost of physical inactivity was estimated at INT$ 54 billion due to direct health costs alone (130); and at a national level, inactivity is estimated to cost between 1–3 % of health-care budgets (131).
Within the wider context of noncommunicable disease (NCD) prevention, additional costs to government and nongovernmental organizations of guideline implementation may be minimized if recommended physical activity can be relatively easily incorporated by individuals into their lives; likewise if existing resources in primary and secondary care, schools, workplaces or transportation can be shifted, resulting in increased physical activity.
Analysis of the cost and benefits of physical activity promotion indicate positive returns on investment over 15 years, in terms of NCD prevention, in many countries where the investment cases have been conducted (132). Interventions such as public education and awareness campaigns and physical activity counselling and referral are a “best buy” and a “good buy” respectively, of recommended interventions to address NCDs based on an update of Appendix 3 of the Global action plan for the prevention and control of NCDs 2013–2020 (133). Overall, the GDG concluded that the benefits of implementing the recommendations outweigh the costs.
Delivering on physical activity guidelines for people with disability may require investment, such as the training of activity specialists, adapted equipment where needed, and facilities that need to be made accessible. These investments can facilitate the needs of a wide range of population groups. Evidence demonstrates a significant participation gradient between people with and without disability in relation to physical activity, due to multiple barriers regarding access, choice of activities offered, and the attitudes of others. Universal design principles should be applied to ensure full and effective participation by people living with disability. With innovation, it is possible to address many of these resource implications. Adopting universal design approaches would mitigate against these costs in the future.
EQUITY, ACCEPTABILITY AND FEASIBILITY
In updating the 2010 recommendations the decision was taken to explicitly include consideration of vulnerable populations, such as those living with chronic conditions and/or disability. The GDG and Steering Group included members representing such groups. The GDG discussed each recommendation at length, considering whether implementing the recommendations would decrease health equity, and the issues related to implementation, to ensure that the recommendations did not worsen equity issues (for example, ensuring that there are safe facilities and opportunities accessible for all, including people living with disability, and socioeconomically and other disadvantaged people, to engage in physical activity; addressing gender and other cultural biases that could restrict access and opportunity to participate in physical activity, etc.). Of respondents to the online public consultation, 76% agreed, or strongly agreed, that implementing the guidelines can achieve a reduction in health inequity by increasing opportunities for all to be active and improve health outcomes. It was noted that supporting environments are key to enabling participation in physical activity. A comprehensive approach to the design and implementation of policies across a number of sectors will be required to address barriers to physical activity for vulnerable groups, such as socioeconomically disadvantaged women and girls, and people with disability.
People with disability experience worse health outcomes than people without disability, yet the benefits of physical activity far outweigh the harms and can be an important intervention to close this health gap. Evidence demonstrates a significant participation gradient between people with and without disability in relation to physical activity, due to multiple barriers regarding access, choice of activities offered, and the attitudes of others. For many people with disability, it should be possible to engage in various forms of physical activity without the need for adapted equipment or facilities. However, in order for people with disability to engage in physical activity on an equal basis with others, adapted equipment may need to be obtained, facilities may need to be made accessible, and activity specialists may need to be trained.
