It is reported that moderate-to-vigorous physical activity (MVPA) is associated with more successful ageing, that is, retaining good cognitive and motor functions and avoiding mental health problems. In the everyday life of senior Chinese people, MVPA is characterised by a variety of informal outdoor activities, including square dancing, shuttlecock kicking, and badminton, football, among others. Some urban leftover spaces, such as spaces between buildings, at the dead ends of streets, and plazas, in front of shopping malls are not designed as activity spaces; they are edges and residual spaces left over after planning. Although shopping mall plazas are ‘designed’ interstitial spaces with regard to their physical characteristics (for example between road and building), from the users’ perspective they can be considered as leftover spaces that can be occupied to a greater or lesser extent. Thus, from a usage point of view, shopping mall plazas can be considered as a subset of leftover spaces. Such leftover spaces can play an important role in facilitating informal sports activities, particularly in densely populated cities like Beijing Core Area where outdoor space is limited. However, studies on how urban leftover spaces can be designed to better support MVPA are lacking.

This work begins by identifying generic parameters that are essential to outdoor space use and urban well-being, including:

• the availability and accessibility of appropriate spaces, park area, sub-areas, type of play courts, a flat area to accommodate different activities, paths/routes, density, distance, space size per capita, the choice of transport, proximity from home;
• amenities, facilities, and aesthetics
  amenities necessary for seniors’ MVPA (fitness equipment disabled access ramps, senior accessibility facilities (e.g., slip-resistant facilities), seating, well-maintained features that can facilitate stretching, good lighting, toilets), amenities that make the space more vibrant (cafes and shops, restaurants), and aesthetically pleasing (green space area, natural area, habitat diversity in natural and green areas, the presence of water, layout, landscaping, visual appeal, plants with contrasting colours and pleasing fragrances etc.;
• microclimate, quality, and privacy
  microclimate, shaded area in summer, quality of roads/cycleways, presence of walking and skiing trails, etc., minimize street noises, buffer planting to create a sense of enclosure around the quieter sub-area; and
• safety, maintenance, and management policies
  safety from crime, safety from traffic, lighting, regular maintenance, the condition of play equipment, visual cues of incivilities, recreational programmes (sports, concerts, races), park design policies, park management practices, and budget procedures.

This study examined the senior citizens’ Shopping-Mall-Plaza-Based Moderate-to-Vigorous Physical Activity (henceforth abbreviated as SMPB MVPA) as an illustration of the potential for urban leftover spaces to facilitate health promotion effects. It investigated the diurnal activity patterns of seniors in six plazas of Beijing through photography and video observation and qualitative surveys. Quantitative observation data are encoded in GIS and analysed descriptively and via regression models. For qualitative data, thematic analyses were performed.

As a result, three categories of key findings were discovered.

(1) Landscape features that facilitate three types of MVPA are identified:

• Group MVPA: This requires sufficient area (on average, 5.63 m² per person for square dancing, 6.63 m² per person for group Tai Chi, 2.18 m² per person for group callisthenics, 1.78 m² per person for group shuttlecock kicking), with group sizes that ranged from 2–109 people (average 27). Spaces also should be segregated from large people flows and close to grass and vegetation (improved further with opportunities to access the grass); they should have adequate lighting, flat ground and electrical outlets for loudspeakers; and the landscape design should include features that inhibit the transmission of sound produced in the space to nearby residents.
• Pairs ball games: This typically requires a larger area (approximately 24.0 m² per pair of badminton players, about 30 m² per pair of soccer players) that is wind proof and has at least two vertical barriers on opposing sides, to prevent the ball from being kicked or hit too far away.
• Individual MVPA: A relatively small area can be exploited (about 3.40 m² for diabolo, 2.50 m² for individual square dancing, and 2.50 m² for individual Tai Chi), with bright illumination for evening activities, fitness equipment or substitutes like handrails about 0.4–1 m in height and horizontal tree branches about 2 m high for chin-up calisthenics. Participants preferred spaces close to lawns and vegetation (with opportunities to access the grass).

(2) Some objective landscape characteristics of shopping mall plazas are associated with a greater number of MVPA participants.

Quantitative research revealed that size (m²) of hard surfaces, lawns, parking lots and disabled access ramps, as well as the number of dustbins, were objectively significant indicators of the number of senior citizens engaging in SMPB MVPA.

(3) Chinese seniors have specific ideas about how shopping mall plazas can be improved facilitate their MVPA more effectively.

Respondents most frequently acknowledged six facilitators: safety, maintenance, accessibility, enclosure by plants, flatness of the ground, and activity space. The open-ended question about other facilitators and barriers yielded nine themes of facilitators: accessibility, microclimate, size, design factors, amenities for seniors’ MVPA, social factors, maintenance, safety, and other factors; and four themes of barriers: size, safety, MVPA-facilitating amenities and social factors.

Findings from this study provide planners, designers, and urban policymakers with recommendations that will enable the establishment of shopping mall plazas that are more attractive for senior citizen MVPA, including:

• Sufficient hard surface area (about 2.80 to 922.94 m², including sufficient area for different kinds of activities, temporal vehicle area and segregated activity areas for different activities, segregation with large people flow) at shopping mall plazas;
• Decent lawn area (an average of 19 per cent of total plaza area – ranging from 0 to 25 per cent);
• Attention to microclimate (opportunity for sunbathing, warmth in winter and coolness in summer, and year-round wind-proofing); and
• Amenities (amenities necessary for seniors’ MVPA such as disabled access ramps, seating, toilets, adequate lighting, electrical outlets for their loudspeakers, and music lowering design to avoid disturbing the nearby residents; amenities making the place more vibrant such as shops, dustbins; flat ground).

It is possible to encourage more seniors to engage in MVPA by equipping shopping mall plazas with the aforementioned characteristics at greater levels. Given that shopping mall plazas are important supplements to other types of green and open space for PA, design interventions at shopping mall plazas are likely to enhance the opportunities for health and well-being of older people, especially in high-density urban settings. Design professionals and policymakers are encouraged to take into account the above suggestions and work together to make shopping mall plazas and other outdoor activity spaces more useful for older people in dense urban areas. Adopting the insights gained from this research would give the senior more opportunities to enhance their physical health and mental well-being.