Rainfall and physical activity; what happens as children age?

Purpose: Weather conditions, along with day length, are proposed as the main drivers of the seasonal patterns in children’s physical activity (PA). This study examines the relationship between rainfall and PA among 9-10 year old children in Norfolk, UK, and how this changes as they age.

Methods: Participants were 283 children from the SPEEDY study who wore accelerometers for up to seven days on three occasions. PA measurements were taken in the school summer terms of 2007, 2008 and 2011 when children were aged 9-10, 10-11, and 13-14 years old. Daily weather data were obtained for two local weather stations. Relationships between rainfall and minutes of moderate-to-vigorous-PA (MVPA; >2000cpm) were assessed in multiple-membership multilevel models allowing for clustering of days within children within both primary and secondary schools.

Results: At ages 9-10 and 10-11 years, MVPA declined with increasing rainfall, with an average of 14.0 (SE 2.9)/11.4 (SE 3.0) minutes less MVPA on the wettest days (≥1.7mm rain; 22% of study days) compared to dry days (0mm rain; 53%) respectively. There was no significant trend in MVPA across rainfall categories at age 13-14 years. Between ages 9-10 and 13-14, MVPA decline was largest on dry days (-15.2 minutes, SE 2.7).

Conclusions: Increased rainfall is associated with significant decreases in MVPA among primary school children, but not secondary school children. MVPA declines most steeply between the ages of 9-10 and 13-14 on dry days. Interventions to increase activity on wet days in primary schools may help increase overall activity levels.