Integrating GPS, Accelerometry and Online Mapping Technologies: Exploring Built Environment Correlates of Adolescent Mobility and Domain-specific Physical Activity
Regular physical activity in youth is associated with many aspects of health and development, yet more than half of New Zealand adolescents struggle to meet physical activity guidelines. The modest results of past physical activity initiatives have fostered a growing consensus that sustainable changes in population physical activity will require built environment change. Despite this, current evidence shows inconsistent and sometimes contradictory associations between the built environment and adolescents’ physical activity. Accounting for wider mobility patterns and improving measurement specificity are consistently acknowledged as avenues of progression. Through a series of five sequential studies, this thesis aims to explore how recent technological innovations can enhance our understanding of how the built environment is related to adolescents’ physical activity and travel behaviours.
The first two studies (Chapters 3 and 4) developed and piloted a novel interactive online mapping tool (VERITAS) for capturing information about adolescents’ mobility and interaction with their environment. Each participant successfully located an average of 18 regularly-visited destinations, as well as travel modes, routes, companions, and perceived neighbourhood spaces. Global Positioning System (GPS) travel records were used to demonstrate the accuracy of routes drawn using the mapping interface. Together, these initial studies revealed the functionality and feasibility of online mapping technology for capturing adolescents’ wider mobility and travel behaviours.
The third study (Chapter 5) was conceived by recognising that research on adolescents’ transport-related physical activity had focused almost exclusively on the school trip. This study integrated GPS and accelerometry to examine how school travel behaviours were representative of wider mobility patterns. Active school travellers (i.e., walk or cycle) accumulated 12.8 min and 14.4 min more moderate-to-vigorous physical activity (MVPA) on weekdays and weekend days, respectively, and spent less time in vehicles during non school trips. However, individuals who did not travel actively to school still achieved most of their MVPA in the transport domain, suggesting that destinations beyond school also provide important travel opportunities.
The fourth study (Chapter 6) attempted to elucidate these findings by integrating VERITAS, GPS, and accelerometry to examine the entirety of destinations that adolescents frequent, and how travel to these destinations was related to physical activity. VERITAS-reported destinations varied markedly in terms of visit frequency, suggesting some destination types were more important than others for providing active travel opportunities. Those who reported using active travel modes for most of their weekly trips walked 1.50 km further per weekday, and 2.25 km further per weekend day, compared to those who reported using passive travel modes.
The final study made pragmatic use of the findings in Chapter 6 by creating an objective and spatially-derived measure of destination accessibility that was relevant to adolescents’ active travel. Accessibility scores were based on the distribution of local destinations around the home, accounting for both destination type and distance from the residence. Adolescents with high destination accessibility achieved 13.9 min more transport-related MVPA and 9.90 min less transport-related sedentary time each day compared to those living in areas of low destination accessibility. These individuals also walked 1.10 km further and travelled 18.6 km less in a vehicle each day. However, total daily MVPA and sedentary time displayed weaker trends, suggesting an element of displacement across physical activity domains.
This body of work demonstrates how recent technologies can be integrated and applied in this research field, and reinforces the importance of capturing domain-specific physical activity and wider mobility patterns in built environment studies. This thesis established that active travel is the primary source of physical activity New Zealand adolescents, and that destination accessibility is strongly associated with transport practices. It is hoped the original information contained within this thesis will contribute to the next generation of physical activity studies, and help encourage the development of more compact cities that promote active living and reduced health inequities.