Background
By 2050, over 2 billion people will be aged 60 or older, with most living in low- and middle-income countries (LMICs). In Latin America, this demographic shift presents challenges for under-resourced health and social systems. Community-based physical activity programs, such as Bogotá’s Recreovía, play a critical role in supporting older adults’ health and well-being. During the COVID-19 pandemic, the program was adapted to offer both outdoor and virtual sessions, aiming to maintain physical activity and social connections despite mobility restrictions. However, there is limited evidence on how such programs influence broader healthy aging outcomes, including mental health and social relationships, particularly during crisis settings. This study describes these outcomes among older adults who participated in Recreovía during the COVID-19 pandemic in Bogotá, Colombia.

Methods
We conducted a mixed-methods study using a simultaneous bidirectional framework design. A survey measured program use and outcomes related to healthy aging, complemented by a network analysis of social relationships. In-depth interviews explored participants’ perceived impacts on quality of life.

Results
Recreovía participation showed significant benefits for older adults’ quality of life. Quantitative data revealed improvements in physical health, mental and psychological well-being. Participants reported enhanced self-esteem, sustained health measures, and strengthened mental resilience. The program also fostered intergenerational relationships, promoted independence, and created supportive peer networks. Qualitative findings highlighted the importance of outdoor environments for physical activity and their holistic contributions to spiritual well-being. The integration of both data sources confirmed these benefits, underscoring Recreovía’s role in enhancing overall well-being and social relationships.

Conclusions
Community-based physical activity programs like Recreovía enhance older adults’ social engagement, foster intergenerational relationships, reduce social isolation, and promote healthy aging. Outdoor spaces that support physical activity and socialization are vital for maintaining independence, mental health, and quality of life. These programs also help older adults sustain relationships and contribute meaningfully to society, promoting a more equitable and supportive environment for healthy aging. By prioritizing the development and support of such spaces and programs, policymakers and community leaders can enhance aging populations’ well-being by prioritizing such initiatives, which are critical for public health strategies in resource-limited settings.

Cities, states, and countries across the globe are recognizing the interconnections of human and planetary health, and are investing in greening. Nevertheless, environmental improvements may not bring adequate changes in exposure needed to reduce chronic disease and improve mental health. Nature prescription, in which a health provider refers a patient to spend time outdoors, is a potential behavioral intervention that could connect people to accessible green spaces. However, formidable patient barriers could reduce the potential to scale-up implementation in equitable and sustained ways. We surveyed 2625 adult respondents within Australia, India, Singapore, the United States, and the United States about their perceptions of a set of seven potential barriers to participation in nature prescriptions. Analyses revealed that respondents in India and Singapore, although most aware of and experienced with nature prescriptions, reported facing greater barriers than in other countries. Weather was the most commonly reported barrier, followed by the lack of time and distance. A lack of interest was a greater barrier among young, urban respondents with a college degree. The barrier of the lack of company was greater for urban residents and for those experiencing financial difficulty. In addition, contrary to many prior studies, we observed greater overall perceived barriers for respondents with higher education levels. Many of the perceived barriers covered by our survey are structurally modifiable, and programs developing in each of these locations may draw from these findings to tailor outreach strategies.

Background
As the world becomes increasingly urbanised, there is recognition that public and planetary health relies upon a ubiquitous transition to sustainable cities. Disentanglement of the complex pathways of urban design, environmental exposures, and health, and the magnitude of these associations, remains a challenge. A state-of-the-art account of large-scale urban health studies is required to shape future research priorities and equity- and evidence-informed policies.

Objectives
The purpose of this review was to synthesise evidence from large-scale urban studies focused on the interaction between urban form, transport, environmental exposures, and health. This review sought to determine common methodologies applied, limitations, and future opportunities for improved research practice.

Methods
Based on a literature search, 2958 articles were reviewed that covered three themes of: urban form; urban environmental health; and urban indicators. Studies were prioritised for inclusion that analysed at least 90 cities to ensure broad geographic representation and generalisability. Of the initially identified studies, following expert consultation and exclusion criteria, 66 were included.

Results
The complexity of the urban ecosystem on health was evidenced from the context dependent effects of urban form variables on environmental exposures and health. Compact city designs were generally advantageous for reducing harmful environmental exposure and promoting health, with some exceptions. Methodological heterogeneity was indicative of key urban research challenges; notable limitations included exposure and health data at varied spatial scales and resolutions, limited availability of local-level sociodemographic data, and the lack of consensus on robust methodologies that encompass best research practice.

Conclusion
Future urban environmental health research for evidence-informed urban planning and policies requires a multi-faceted approach. Advances in geospatial and AI-driven techniques and urban indicators offer promising developments; however, there remains a wider call for increased data availability at local-levels, transparent and robust methodologies of large-scale urban studies, and greater exploration of urban health vulnerabilities and inequities.

Recent advances in data science and urban environmental health research utilise large-scale databases (100s–1000s of cities) to explore the complex interplay of urban characteristics such as city form and size, climate, mobility, exposure, and environmental health impacts. Cities are still hotspots of air pollution and noise, suffer urban heat island effects and lack of green space, which leads to disease and mortality burdens preventable with better knowledge. Better understanding through harmonising and analysing data in large numbers of cities is essential to identifying the most effective means of disease prevention and understanding context dependencies important for policy.

Evidence to support nature contact and nature prescriptions to reduce loneliness is scant. A total of 2100 individuals took part in a survey conducted in Australia (n = 525, mean age = 34.1), India (n = 526, mean age = 29.5), Singapore (n = 523, mean age = 36.1), the UK (n = 526, mean age = 37.3), and the US (n = 525, mean age = 43.6) in 2022 (overall age range 18–89yrs). Multilevel logistic regressions adjusted for confounding indicated mean levels of overall loneliness tended to be higher in India (Odds Ratio [OR] 1.21, 95% Confidence Interval [95%CI] 0.90–1.62), Singapore (OR = 1.54, 95%CI = 1.15–2.07), the UK (OR = 1.26, 95%CI = 0.96–1.67) and the US (OR = 1.24, 95%CI = 0.94–1.64) compared with Australia. Notable differences were observed by loneliness type, for example, with lower odds of social loneliness (OR = 0.57, 95%CI = 0.41–0.79) and higher odds of emotional loneliness (OR = 1.57, 95%CI = 1.14–2.06) in India compared with Australia. Findings with regards to loneliness and nature contact varied between country. In general, social loneliness was lower in participants who visited natural surroundings regularly (OR = 0.81, 95%CI = 0.61–0.98) and spent two hours or more per week in nature (OR = 0.65, 95%CI = 0.49–0.81). Overall loneliness (OR = 1.98, 95%CI = 1.48–2.47) and emotional loneliness (OR = 2.84, 95%CI = 2.13–3.51) were substantially higher among those who felt having no-one to go with was a barrier to spending time in nature. Emotional loneliness was higher in those who had more time in nature (OR = 1.32, 95%CI = 0.94–1.75) or more frequent visits (OR = 1.24, 95%CI = 0.94–1.49), which may be indicative of selective processes by which some people who feel emotionally lonely seek meaningful sources of connection or solace in natural environments. In sum, these findings highlight potentially important contingencies in how people feel lonely in different countries, and the potential of contact with nature as a means to address this critical issue of modern times. Randomised trials of nature prescription interventions for loneliness co-designed with respect to contrasting cultural, economic, and climatic contexts are needed to ensure programs intended to reconnect people with nature are effective, equitable, and acceptable for everyone.

Measuring and monitoring progress towards achieving healthy, equitable and sustainable cities is a priority for planners, policymakers and researchers in diverse contexts globally. Yet data collection, analysis, visualisation and reporting on policy and spatial indicators involve specialised knowledge, skills, and collaboration across disciplines. Integrated open-source tools for calculating and communicating urban indicators for diverse urban contexts are needed, which provide the multiple streams of evidence required to influence policy agendas and enable local changes towards healthier and more sustainable cities. This paper reports on the development of open-source software for planning, analysis and generation of data, maps and reports on policy and spatial indicators of urban design and transport features for healthy and sustainable cities. We engaged a collaborative network of researchers and practitioners from diverse geographic contexts through an online survey and workshops, to understand and progressively meet their requirements for policy and spatial indicators. We outline our framework for action research-informed open-source software development and discuss benefits and challenges of this approach. The resulting Global Healthy and Sustainable City Indicators software is designed to meet the needs of researchers, planners, policy makers and community advocates in diverse settings for planning, calculating and disseminating policy and spatial urban indicators.

Purpose
The purpose of this study was to describe the association between sedentary time and social engagement among older adults living in megacities in India.

Design/methodology/approach
Data from a cross-sectional survey conducted in New Delhi and Chennai were used for analysis. In the total sample (n = 528), 65% of older adults self-reported engaging in high (≥180 min/day) volumes of sedentary time. There were no associations between sedentary time and social engagement in older females.

Findings
Among older males, those reporting high levels of communicating or visiting with family and friends had lower odds of reporting ≥ 180 min/day of sedentary time (OR: 0.51, CI: 0.27–0.98) compared to those reporting low levels of this type of social engagement. Older males reporting high levels of participating in a club (OR: 2.27, CI: 1.19–4.3) or participating in religious activities (OR: 1.97, 1.01–3.85) were approximately two times more likely to report ≥ 180 min/day sedentary time compared to those reporting low levels of these types of social engagement.

Originality/value
These data suggest that the type of social activity appears to significantly affect self-reported sedentary time among older males, but not females. These findings have implications for interventions aimed at improving active aging among older adults living in megacities in India.

The community restrictions during the coronavirus disease 2019 pandemic adversely impacted older adults’ physical activity levels. This convergent mixed-method study assessed the adaptation of the Recreovía, a community-based physical activity program in Bogotá, and characterized physical activity levels among older adult participants. Our results showed how the Recreovía adapted during the pandemic to continue promoting physical activity, through indoor and outdoor strategies, including virtual physical activity sessions and safety protocols. During this time, 72%–79% of the older adults attending the adapted program were physically active. A greater proportion of park users (84.2%) and more people involved in vigorous physical activity were observed during Recreovía days. Older adults had positive experiences and perceptions of the Recreovía program related to their health and social well-being. Even though the older adults prefer being outdoors, the adapted program allowed participants to continue with their physical activity routines as much as possible during the pandemic.

Uneven access to greenspaces or visible greenness is an environmental justice (EJ) issue. In this paper, we use a social equity lens to develop geospatial models that measure convenient walking access to urban greenspaces such as parks and street-level green exposure en route to greenspaces. We utilized earth science, geospatial, and demographic datasets to develop two models—Greenspace Accessibility and Visible Greenness Exposure—and applied them in Camden and Jersey City, USA, two communities experiencing environmental injustices. Modeling results show that greenspace accessibility is a concern in both cities, with Jersey City experiencing more prominent disparities. We observed significant positive relationships in Camden between greenspace accessibility and two EJ variables: Black segregation and Hispanic segregation. Most streets in both cities have poor greenness exposure, although Jersey City faces higher inequality compared to Camden. We also observed significant negative relationships in Jersey City between street-level greenness exposure and low-income populations. We conclude the paper by explaining the implications of our findings for greenspace planning and policymaking.

Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion.

Given its origins in high-income countries, the field of physical activity and public health research and promotion has broadly followed a choice-based model. However, a substantial amount of the physical activity occurring routinely in many settings, particularly in low- and middle-income countries (LMICs), is the result of economic necessity and is not due to true, free choices. We propose the necessity- versus choice-based physical activity models framework as a conceptual tool to ground physical activity and public health research and promotion efforts in LMICs, helping ensurethat these efforts are relevant, ethical, responsive, and respectful to local contexts. Identifying ways to ensure that LMIC populations can maintain high levels of active transport while increasing opportunities for active leisure must be prioritized. To promote equity, physical activity research, programs, and policies in LMICs must focus on improving the conditions under which necessity-driven physical activity occurs for a vast majority of the population.

In the early stages of the COVID-19 pandemic, dubious assertions that population density increased spread of the virus led to premature and dangerous recommendations promoting suburban sprawl. In 2020, we published a commentary in Cities & Health to refute these recommendations. We hypothesized that features of activity-supportive environments, including high density, would be protective from severe COVID-19 outcomes. The goal of the present commentary is to examine evidence that has emerged during the pandemic to evaluate veracity of the predictions and recommendations we made in 2020. An updated analysis of cities from each continent supports our 2020 analysis that population density is not associated with COVID-19 mortality. Our earlier recommendations to promote activity-supportive environments to benefit both infectious and non-communicable diseases, and to ensure equity of access to such environments, are now supported by empirical studies. Evidence related to public transport shows mitigation of risk could be achieved by limiting riders, travelling during off-peak hours, enforcing physical distancing, requiring face coverings, and implementing strict cleaning protocols. There is substantial evidence that environmental features and interventions that support COVID-19 mitigation strategies also have additional health, environmental sustainability, and economic benefits.

Objective: “Nature prescriptions” are increasingly being adopted by health sectors as an adjunct to standard care to attend to health and social needs. We investigated levels of need and interest in nature prescriptions in adults with cardiovascular diseases, psychological distress and concomitants (e.g. physical inactivity, sedentary behaviour, obesity, loneliness, burn-out). Methods: A nationally-representative survey of 3,319 adults across all states and territories of Australia was completed in February 2021 (response 84.0%). Participants were classified across 15 target groups using validated health indicators and surveyed on (1) time and frequency of visits to green and blue spaces (nature spaces), (2) interest in a nature prescription, and (3) potential confounders (e.g. age, income). Analyses were done using weighted logistic regressions. Results: The sample was 50.5% female, 52.0% were aged ≥45 years, 15.2% were living alone and 19.3% were born overseas in non-English-speaking countries. Two-thirds of the sample spent 2 hours or more a week in nature, but these levels were generally lower in target groups (e.g. 57.7% in adults with type 2 diabetes). Most participants (81.9%) were interested in a nature prescription, even among those spending fewer than 2 hours a week in nature (76.4%). For example, 2 hours a week or more in nature was lowest among sedentary adults (36.9%) yet interest in nature prescriptions in this group was still high (74.0%). Lower levels of nature contact in target groups was not explained by differences in access to or preference for local nature spaces. Conclusions: High levels of interest in nature prescriptions amid low levels of nature contact in many target health groups provides impetus for developing randomised trials of interventions that enable people to spend more time in nature. These findings can inform intervention co-design processes with a wide range of community stakeholders, end-users in target health groups, and the health professionals who support them.

This chapter discusses the inclusion and integration of a preliminary analytical person-environment fit framework which recognises the urban context as a key health determinant worldwide. It has become necessary to respond to growing levels of sedentarism, identified as a major risk factor for non-communicable diseases, through incremental and tailored interventions, based on the ideas of complex adaptive systems. It is proposed that this framework can help to integrate and acknowledge the needs of older adults as a differentiated group where health models which concentrate on older adults as a unique and specialised demographic are called for in order to further research in understanding the pathways and mechanisms shaping their health behaviours, in particular highlighting internalised and individualised responses, understood here as concepts of fit between the individual and their surrounding neighbourhood and environments.

As cities and urban centres grapple to respond to ageing populations, there is a heightened awareness that the urban environments we live in play a key part in improving people’s health and wellbeing. Environments that are planned, managed, and inclusive in terms of spatial and physical form can help to promote and encourage health equity and wellbeing beyond a traditional ‘pathogenic’ focus on health risks and can provide a baseline for placing cities at the core of a more embracing understanding of the relationship between health and urban environments for older adults.

Creating healthy and sustainable cities should be a global priority. Some cities prioritize 15-minute cities as a planning approach with co-benefits for health, climate change mitigation, equity, and economic recovery from COVID-19. Yet, as our recent Lancet Global Health series on “Urban Design, Transport, and Health” showed, many cities have a long way to go to achieve this vision. This policy guideline summarizes the main findings of the series, which assessed health and sustainability indicators for 25 cities in 19 countries. We then outline steps governments can take to strengthen policy frameworks and deliver more healthy, equitable, and sustainable built environments.

The Lancet Global Health series provided clear evidence that cities need to transform urban governance to enable integrated planning for health and sustainability and commit to policy implementation. Evidence-informed indicators should be used to benchmark and monitor progress. Cities need policy frameworks that are comprehensive and consistent with evidence, with measurable policy targets to support implementation and accountability. The series provided evidence-informed thresholds for some key urban design and transport features, which can be embedded as policy targets. Policies and interventions must prioritize identifying and reducing inequities in access to health-supportive environments. Governments should also invest in open data and promote citizen-science programmes, to support indicator development and research for public benefit. We provide tools to replicate our indicators and an invitation to join our 1000 Cities Challenge via the Global Observatory of Healthy and Sustainable Cities.

Physical inactivity is the fourth leading risk factor for global mortality, causing an estimated 3.3 million deaths worldwide. Characteristics of the built environment, including buildings, public spaces, pedestrian and cycling infrastructure, transportation networks, parks, trails and green spaces can facilitate or constrain physical activity. However, objective study of built environment interventions on physical activity remains challenging due to methodological limitations and research gaps. Existing methods such as direct observations or surveys are time and labour intensive, and only provide a static, cross-sectional view of physical activity at a specific point in time. The aim of this study was to develop a novel method for objectively and inexpensively assessing how built environment changes may influence physical activity. We used a novel, unobtrusive method to capture real-time, in situ data from a convenience sample of 25 adults along a newly constructed urban greenway in an area of high deprivation in Belfast, UK. Walk/bike-along interviews were conducted with participants using a body-worn or bicycle-mounted portable digital video camera (GoPro HERO 3+ camera) to record their self-determined journeys along the greenway. This is the first study to demonstrate the feasibility of using wearable sensors to capture participants’ responses to the built environment in real-time during their walking and cycling journeys. These findings contribute to our understanding of the impact of real-world environmental interventions on physical activity and the importance of precise, accurate and objective measurements of environments where the activity occurs.

An essential characteristic of a healthy and sustainable city is a physically active population. Effective policies for healthy and sustainable cities require evidence-informed quantitative targets. We aimed to identify the minimum thresholds for urban design and transport features associated with two physical activity criteria: at least 80% probability of engaging in any walking for transport and WHO's target of at least 15% relative reduction in insufficient physical activity through walking. The International Physical Activity and the Environment Network Adult (known as IPEN) study (N=11 615; 14 cities across ten countries) provided data on local urban design and transport features linked to walking. Associations of these features with the probability of engaging in any walking for transport and sufficient physical activity (≥150 min/week) by walking were estimated, and thresholds associated with the physical activity criteria were determined. Curvilinear associations of population, street intersection, and public transport densities with walking were found. Neighbourhoods exceeding around 5700 people per km², 100 intersections per km², and 25 public transport stops per km² were associated with meeting one or both physical activity criteria. Shorter distances to the nearest park were associated with more physical activity. We use the results to suggest specific target values for each feature as benchmarks for progression towards creating healthy and sustainable cities.

Pedestrian accessibility is an important factor in urban transport and land use policy and critical for creating healthy, sustainable cities. Developing and evaluating indicators measuring inequalities in pedestrian accessibility can help planners and policymakers benchmark and monitor the progress of city planning interventions. However, measuring and assessing indicators of urban design and transport features at high resolution worldwide to enable city comparisons is challenging due to limited availability of official, high-quality, and comparable spatial data, as well as spatial analysis tools offering customizable frameworks for indicator construction and analysis. To address these challenges, this study develops an open source software framework to construct pedestrian accessibility indicators for cities using open and consistent data. It presents a generalized method to consistently measure pedestrian accessibility at high resolution and spatially aggregated scale, to allow for both within- and between-city analyses. The open source and open data methods developed in this study can be extended to other cities worldwide to support local planning and policymaking. The software is made publicly available for reuse in an open repository.