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.

Executive SummaryThe poor physical health of people with mental illness is a multi-faceted, transdiagnostic, and global problem. Physical health disparities are observed across the entire spectrum of mental illnesses, in low, middle-and high-income countries. This stems from both a heightened risk of physical diseases in people with mental illness, along with their reduced access to adequate healthcare. The high rates of physical comorbidities (and typically-poor clinical management of this) drastically reduces life expectancy, and also increases the personal, social and economic burden of illness across the lifespan.This Commission has brought together an international team of researchers, clinicians, and key stakeholders from various backgrounds and professionally / personally-relevant experience, in order to summarize advances in understanding on this topic, and present clear directions for health promotion, clinical care and future research. The breadth and multifactorial nature of physical health disparities across the range of mental health diagnoses poses an almost limitless number of potential considerations. Therefore, rather than attempting to cover all of the different possible combinations of physical-mental comorbidities individually, the aim of this Commission was to: (i) establish highlypertinent aspects of physical health-related morbidity and mortality which apply transdiagnostically, (ii) highlight the common modifiable factors driving these disparities, (iii) present actions and initiatives for health policy and clinical services to address these issues, and (iv) identify promising areas for future research towards discovering novel solutions. This was addressed across 5 different Parts of the Commission: Parts 1 and 2 determined the scope, priorities and key targets for physical health improvement across multiple mental illnesses. Parts 3, 4 and 5 discussed emerging strategies and produced recommendations for improving physical health outcomes in people with mental illness. Leaders and contributors for each Part are shown in the Appendix (pg.1) . Part 1: 'Its more than premature mortality'Part 1 identified almost 100 systematic reviews/meta-analyses examining the prevalence of physical comorbidities in mental illness. Around 70% of the meta-research focused on cardiometabolic diseases; consistently reporting that mental illnesses were associated with 1.4-to 2-fold increased risk for obesity, diabetes and cardiovascular diseases compared to the general population. Although mostly studied in 'severe mental illness' ('SMI', and particularly psychotic disorders), the prevalence of cardiometabolic diseases was similarly elevated across a broad range of other diagnoses, including substance use disorders (SUDs), and 'common mental disorders' ('CMDs', such as depression and anxiety). Part 2: Key modifiable factors in health behaviours and health servicesPart 2 built on the findings of Part 1 with a hierarchal evidence synthesis of modifiable risk factors for physical diseases in mental illness. The bu...