Public transit use and physical activity in community-dwelling older adults: Combining GPS and accelerometry to assess transportation-related physical activity

Abstract

Abstract Background Emerging evidence shows that public transit use is associated with greater physical activity levels in adults through higher levels of transportation-related walking. However, little is known about the health benefits of public transit use in older adults. Purpose To assess transportation-related and overall physical activity in community-dwelling older adults from downtown Vancouver, a highly walkable area with good access to public transit. Methods Older adults (65% female; 70.3±0.5 years) from downtown Vancouver wore accelerometers (ActiGraph GT3X+, 1 s epoch) and GPS (QStarz BT-Q1000XT, 1 s epoch) for 7 days in Fall 2012. We identified trips from time-aligned GPS and accelerometry data ( n =2973 trips made by n =178 individuals) and calculated trip duration, distance, speed, and transportation-related moderate-to-vigorous physical activity (MVPA; minutes). We assessed between-mode differences and associations using multilevel linear regression analyses. Results Walk trips were most common ( n =1800; 61%), followed by car trips ( n =746; 25%), public transit trips ( n =310; 10%) and bicycling trips ( n =117; 4%). Overall, public transit trips accrued similar amounts of MVPA compared with walk trips (median: 5.5 vs. 4.8 min). Nearly all participants walked ( n =175/178), but less than half used public transit ( n =74/178). In transit users, daily MVPA was significantly lower on days on which they did not use transit compared with days when they did (47.6 vs. 56.3 minutes), which was almost entirely explained by differences in transportation-related MVPA between those days (difference: 7 minutes). Conclusions Active transportation, including public transit use, may contribute meaningfully to daily physical activity levels in community-dwelling older adults.