Association of low physical activity with higher respiratory tract infections frequency among pre-school children.

Background: There is no consensus on the benefits of physical activity (PA) regarding upper respiratory tract infections (URTIs) among children. This study aimed to determine an association between the PA level and URTIs in preschoolers.

Methods: In 4-7-year-old participants, URTI symptoms were monitored using the Polish version of the Wisconsin Upper Respiratory System Survey for Kids. The daily number of steps, PA intensity, and sleep duration were measured with a Garmin-vivofit pedometer. The lag effect between the initial level of daily PA and the frequency of infections was evaluated.

Results: The average daily step count from healthy days was a significant determinant of the total number of days with the URTI symptoms, and it accounted for 44% (p < 0.001) of this variable variance. A low level of baseline PA (initial 14-day "run-in" observation period) was associated with an increased risk of URTI. In the non-sport group, the severity of the URTI symptoms depended on the number of daily steps. No significant correlation was found between sleep duration and the number of URTI days.

Conclusion: Low levels of PA in preschoolers result in increased susceptibility to respiratory infections. Parents should encourage children to engage in PA to prevent URTIs.

Impact: In pre-school children, higher physical activity (PA) is associated with fewer days of upper respiratory tract infection symptoms (URTIS). Children with a higher average daily step count have fewer days with URTIS over a long-term observation period. A change in the average number of steps per day by 1000 changed the number of days with symptoms of URTI by 4 days. The severity of URTIS was inversely related to the degree of PA. Children who participate in sports 3 or more hours per week have fewer URTIS than those who do not engage in sports regularly.