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.
摘要：
美国的个人不够活跃，增加他们的慢性病风险。由于热不适，极端温度可能会减少身体活动。较凉爽的气候研究表明，气候变化可能对身体活动产生净积极影响，然而，对于温暖的气候和一天内的身体活动模式，研究仍然存在差距。我们确定了潮湿的亚热带气候中环境温度（当代和预计）与城市步道使用之间的关联。在奥斯汀的一条小径上，TX,五个电子柜台在2019年记录了每小时行人和骑自行车的人数。天气数据是从世界天气在线获得的。广义加法模型估计了温度和踪迹计数之间的关联。然后，我们将NASANEX-GDDP针对中等（RCP4.5）和高（RCP8.5）排放情景的气候模型的估计暴露-响应关系与天气预测相结合。从夏天到秋天到春天到冬天，每小时的步道计数从双峰（上午和傍晚的高峰）转移到一个中午的高峰。行人更有可能在7至27°C（45-81°F）之间使用小径，峰值在17°C（63°F）使用，而骑自行车的人在15至33°C（59-91°F）之间使用峰值在27°C（81°F）比在极端温度下使用。估计到2041-2060年，步道使用量净减少(RCP4.5：行人=-4.5%，骑车人=-1.1%；RCP8.5：行人=-6.6%，骑车人=-1.6%)和2081-2100(RCP4.5：行人=-7.5%，骑车人=-1.9%；RCP8.5：行人=-16%，骑自行车的人=-4.5%)。结果表明，气候变化可能会减少小径的使用。我们建议在身体活动设置时进行热舒适干预。
