Climate change and physical activity: ambient temperature and urban trail use in Texas

Abstract

Individuals in the USA are insufficiently active, increasing their chronic disease risk. Extreme temperatures may reduce physical activity due to thermal discomfort. Cooler climate studies have suggested climate change may have a net positive effect on physical activity, yet research gaps remain for warmer climates and within-day physical activity patterns. We determined the association between ambient temperatures (contemporary and projected) and urban trail use in a humid subtropical climate. At a trail in Austin, TX, five electronic counters recorded hourly pedestrian and cyclist counts in 2019. Weather data were acquired from World Weather Online. Generalized additive models estimated the association between temperature and trail counts. We then combined the estimated exposure–response relation with weather projections from climate models for intermediate (RCP4.5) and high (RCP8.5) emissions scenarios by NASA NEX-GDDP. From summer to autumn to spring to winter, hourly trail counts shifted from bimodal (mid-morning and early-evening peaks) to one mid-day peak. Pedestrians were more likely to use the trail between 7 and 27 °C (45–81°F) with peak use at 17 °C (63°F) and cyclists between 15 and 33 °C (59–91°F) with peak use at 27 °C (81°F) than at temperature extremes. A net decrease in trail use was estimated by 2041–2060 (RCP4.5: pedestrians = − 4.5%, cyclists = − 1.1%; RCP8.5: pedestrians = − 6.6%, cyclists = − 1.6%) and 2081–2100 (RCP4.5: pedestrians = − 7.5%, cyclists = − 1.9%; RCP8.5: pedestrians = − 16%, cyclists = − 4.5%). Results suggest climate change may reduce trail use. We recommend interventions for thermal comfort at settings for physical activity.

Heat-Resilient Schoolyards: Relations Between Temperature, Shade, and Physical Activity of Children During Recess

“…In another study in Austin, TX, researchers found pedestrians were more likely to use a hike and bike trail until 27 °C (81 °F) after which trail use decreased. 14 The different temperature values at which the regression slope changes between this study and ours may be related to differences in setting and type (ie, active transportation vs scheduled free play) of physical activity 41 impacting the behavioral threshold for heat.…”

“…Physical activity and thermal comfort of children may be maximized by scheduling recess during cooler morning hours when researchers have found more pedestrians using a hike and bike trail in Austin, TX, on extreme heat days than other times. 14 In choosing when to schedule recess, schools should strike a balance between maximizing thermal comfort for physical activity promotion, providing a mental break from classroom instruction, and splitting up sedentary time during the school day.…”

“…A study of a hike and bike trail in Austin, Texas, United States, revealed that trail use was more likely by pedestrians until 27 °C (81 °F) and cyclists until 33 °C (91 °F) after which trail use decreases. 14 Among the few studies exploring the temperaturephysical activity relationship for children, summer months and days with higher temperatures exhibited negative associations with physical activity. [15][16][17][18] Traditional schoolyard design-high amounts of impervious materials and few trees-results in high surface temperatures.…”

The Impact of Temperature on 24-Hour Movement Behaviors among Chinese Freshmen Students

“…Third, studies that consider PA, SB and sleep duration at temperatures among different seasons are lacking. With continued greenhouse gas emissions and global warming due to urban development, we need to consider combining temperature management strategies with PA interventions to potentially promote comfortable and safe PA [ 35 ]. The freshmen are in a transitional phase from adolescence to adulthood, a critical time for developing healthy lifestyles and healthy behaviors.…”

A direct observation tool to measure interactions between shade, nature, and children’s physical activity: SOPLAY-SN

“…PA intensity during recess may be modified by individuals' heat exposure and associated level of thermal comfort. With climate-related factors becoming increasingly recognized as drivers of PA [29][30][31], incorporating measures of heat exposure and shade during recess is particularly relevant in warm climates. For instance, in the humid subtropical climate of Austin, Texas, children were more likely to be observed under tree canopy during high ambient temperatures compared to lower temperatures, potentially seeking shade for thermal comfort [32].…”