Physical Activity and the Built Environment
The environment is integral to encouraging physical activity. The built environment is an aspect of the environment that is increasingly receiving research attention. Recommended levels of physical activity can be achieved by including activities such as walking, cycling as part of everyday life. This can be encouraged with a supportive built environment. Even though individual and social factors affect physical activity, research has shown that a well-designed environment matters.
The built environment is defined as the part of the physical environment that is constructed or modified by human activity. It includes homes, schools, workplaces, parks or recreation areas, green-ways, business areas and transportation systems. In public health, a built environment refers to physical environments that are designed with health and wellness as integral parts of communities and it has features like open spaces, footpaths, cycle lanes, parks, trails. The emphasis on the role of built environment is necessary as encouraging people to be more physically active in an environment that is not supportive is less likely to be effective.
Physical activity can be classified into four domains of life that describe how people spend their time: recreational, occupational, transport and household activities. Recreational and transport physical activity are relevant to and driven by the built environment features. Physical activity is promoted by the built environment through walkable neighbourhoods, presence of sidewalks, walking paths and bike paths and presence of recreational and sports infrastructure including parks, pools, playgrounds, and sport clubs.
Using the built environment as an intervention for improving physical activity offers numerous advantages. Diverse to individual level approaches, developing a supportive environment has the potential to achieve biggest reach for long term, population-wide improvements in physical activity levels and facilitate behaviour change maintenance. Also, physical activity interventions that reach a large numbers of people over a sustained period of time are often more cost effective than individual level interventions.
Features of Built Environment
Built environment features that are hypothesised to be associated with recreational and transport activity have been divided into four categories;
- Recreational resources: walking trails, biking trails, parks and open spaces
- Land use characteristics: residential and employment density, land use mix (types of buildings, services and businesses in the community), street connectivity (grid pattern, cul-de-sac and loop holes) and proximity of destinations (shops, employment and services) to residences.
- Neighbourhood form characteristics: availability of sidewalks and street light
- Community environment: mostly contextual features of the environment such as aesthetics, cleanliness, traffic, crime safety or community support or cohesion.
Specific features of the built environment that has been found to correlate with physical activity levels include mixed land use, residential density and street connectivity.These features have the potential to influence walking for recreational and travel related physical activity. For instance, presence of sidewalks and streetlights might make recreational activity more appealing. Meanwhile, proximity to destinations and grid like street patterns might make it easier or more pleasant to walk or bicycle for transportation.
The extent to which the built environment is friendly to the presence of people living, shopping, visiting, enjoying or spending time in the area is termed “Walkability.” A walkable neighbourhood is one that is densely populated, where several businesses and services are present, where the streets are well connected to facilitate easy access by active transportation. Walking and cycling facilities like sidewalks, crosswalks, and bike lanes are also present in a walkable neighbourhood. In contrast, high urban sprawl is characterised by low land use density, low residential density, absence of a downtown and less street connectivity. Walking, cycling and public transport are made impractical with high urban sprawl and as such are associated with sedentary lifestyles.
- Residential density refers to the number of residential units per unit of land area. It means more destinations such as shops, services, and public transport stops nearby. 
- Land use mix diversity refers to the level of integration within an area of different types of uses for physical space. This includes residential, office, retail, industry and public space.
- Street connectivity refers to the ease of travel between two points which is directly related to characteristics of street design. It's characterised by many interconnected streets.
- Accessibility refers to the ease by which desired places or activities can be reached and refers to the land use system and transportation system.
The design and maintenance of neighbourhoods, streets, parks and people’s perception of those places based on qualities such as aesthetic appeal and perceived safety can affect physical activity in adults and youths. For leisure walking, the perceived aesthetics- visual appeal or pleasantness of an environment- and safety from crime and traffic can affect walking. Aesthetic features of the neighbourhood provide an inviting setting for physical activity.
Studies relating attributes of neighbourhood environments and physical activity particularly within the U.S, Australia and a few European nations found that walkable neighbourhoods characterised by high density, well connected grid-like street networks and accessible and diverse destinations within walking distance were associated with active transportation, particularly walking for transport. Additionally, access to parks and recreation facilities shows significant associations with recreational physical activity. The presence of existing and new public transportation options in neighbourhoods appears associated with greater physical activity.
Relationship between Physical Activity and Built Environment
Significant positive association between features of the built environment and physical activity has been established by a number of studies. The relationship may vary on the basis of the domain of physical activity. Recreation and transportation domains of physical activity are mostly influenced by the built environment. It can also have a dissimilar influence on these domains of physical activity. For instance, a highly connected street can be beneficial for walking for transportation to destinations but detrimental for active play in the streets for children. Walking and bicycling for transportation and/ or leisure are a major form of physical activity worldwide and such activities can meet recommendations for physical activity.
Street connectivity is a feature of the built environment that could have direct influence on physical activity, particularly walking. Well connected street networks create routes that are shorter to destinations which ease walking from place to place. Grid streets designs assists pedestrian movement with two characteristics; frequent intersections and orthogonal geometry.
Sidewalks and bike paths in neighbourhoods promotes active transportation. People feel safer and enjoy activity more with these features. Placing residential and commercial areas in close proximity helps to reduce reliance on automobiles while encouraging active transportation.The routes linking destinations should encourage biking and walking. Having bike paths that separate bicycles from traffic is sometimes associated with increased bike use. When public bus and rail stops are nearby, it promotes active transport by ensuring people walk to and fro public transit.
Public open spaces encourage physical activity during leisure time among the populace. They provide places for individuals to walk to as a destination and also have facilities for sports, exercise and other vigorous activities. They must be located nearby, easily accessed by residents and have amenities of good quality. Playgrounds and parks are more attractive for physical activity when people's perception of them is safe and pleasant. Children, families and organisations prefer to visit and spend time in appealing places.
Attractiveness of the neighbourhood environment is also associated with recreational walking. Neighbourhood aesthetics such as cleanliness, attractive natural sights- landscaping and views promotes walking for recreation. Walking is pleasant for residents with aesthetic neighbourhoods.
Finally, a built environment that is safe, attractive, promotes easy access to healthy food and variety of opportunities to be physically active daily is considered conducive to the adoption of healthy lifestyles.
Recommendations for Environment and Policy Change
Public health professionals need to build collaborations across multiple disciplines such as transportation, urban planning, architecture and public health law that would help to encourage healthy community design. Policies that recommend changing the built environment to increase population level physical activity are influenced by evidence based data. Hence, the need for high quality data on the broader impacts of the built environment on physical activity.
Physiotherapists use exercise- a subcategory of physical activity as part of therapy for rehabilitation, PTs should endeavour to educate their patients on the use of the built environment for physical activity. It's not sufficient to have the built environment favourable for physical activity, people have to put it to its best use.
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