Physical Activity and Weather: The Association of Physical Activity with Weather-Related Factors Measured on the Knoxville Third-Creek Greenway

The primary purpose of this study was to examine the association of outdoor physical activity (PA) with weather-related factors (temperature, humidity, heat index, and precipitation) when data was measured onsite (Knoxville Third-Creek Greenway). Secondary to this research question, this study explored whether the source of weather­ related data (site-specific vs. public domain) influenced the strength of association with outdoor PA. PA, the dependent variable, was measured as trail counts by an infrared trail counter. Weather-related factors were obtained by an on-site weather station and through the National Oceanographic and Atmospheric Administration (NOAA), a public domain weather source. Hourly PA (trail counts) and weather-related factors were matched and analyzed using correlations, dependent correlation comparisons, and linear regression modeling. Statistical analysis showed that weather-related measures from both onsite and public domain weather sources were moderately correlated with PA. Weather-related factors explained approximately 13% and 20% of the variance in PA on weekdays and weekends, respectively, regardless of the source of weather related data. The amount of variance explained by weather-related factors in this study was 2-3 times more variance reported than any other study to date. The analysis of PA and weather-related data at the hourly level, as opposed to aggregated daily averages, may have increased the precision to detect differences in PA levels due to weather-related measures. Weather-related factors have a moderate association with outdoor PA. The association of PA with weather-related measures was different on weekdays compared to weekend days. No practical differences were found between weather-related measures