Effects of Heating & Cooling Degrees, Precipitation, and Wind Speed On Childhood Physical Activity
Purpose To evaluate the effect of local weather conditions on physical activity (PA) in 3-7 year old children.
Methods This study enrolled 372 children and objective measures of total (T)PA (RT3, triaxial accelerometer) were collected for 3 days every 4 mo from age 3 to age 7 y from 2001-2006. Weather information (temperature maximum/minimum, precipitation, wind speed) from the local municipal airport was obtained from the US National Climatic Data Center and merged with 9,264 participant-days of PA data. Heating and cooling degrees, a measure used to estimate energy requirements for geographic areas in the form of degree days, were calculated using 65 degrees Fahrenheit (F) as a basis. Pearson correlation coefficients were calculated between PA variables (counts per minute (cpm), minutes Moderate/Vigorous PA) and weather variables. Multivariate regression was used to test the relationship between weather and PA.
Results Temperatures ranged between -8 to 100 degrees F over the duration of the study. Mean daily precipitation was 0.1 inches and wind speed mean was 6 mph. Across the 5 years of the study, mean total PA was 609 ± 258 (standard deviation) and mean MVPA was 88 ± 57 minutes. Both TPA (r = -0.15) and MVPA (r = -0.16) were both significantly negatively correlated with cooling/heating degrees (P < 0.0001). They were significantly negatively associated with precipitation (r = 0.07 for both) and wind speed (r = -0.06 for both) (P < 0.0001). Heating/cooling degrees were significantly associated with TPA and MVPA independent of precipitation and wind speed. Each 10 additional heating/cooling degrees in the model was associated with 8 minutes less MVPA.
Conclusion More extreme weather (higher or lower temperatures, higher wind, more rain/snow) is associated with decreased physical activity in young children. As weather patterns become more extreme, PA interventions should be designed and tested with consideration of weather effects. Supported in part by grants: NIH NHLBI R01HL064022, NCATS KL2TR000078, & the CCHMC Heart Institute Research Core.