RESEARCHERS have concluded that children of preschool age who are physically active spend less days with symptoms of upper respiratory tract infections (URTI) than their peers who take up less physical exercise.
In a cross-sectional study with a single population, researchers from the Medical University of Warsaw, Poland, looked at a cohort of 104 children (mean age: 5.3 years; 55 females) aged between 4–7 years, and living in the Warsaw City region.
The study evaluated symptoms of URTI every day for a period of 60 days, using parental reports taken from the Polish equivalent of the Wisconsin Upper Respiratory System Survey for Kids. All participants wore the Vivofit fitness band (Garmin, Kansas, USA), and their daily steps, sleep duration, and activity intensity were tracked 24 hours a day for 40 days.
During the observation period, researchers found that the median total number of days with symptoms of URTI was 26 (range: 6–58), typical for both the age group and season. An increase of 1,000 steps per day was found to lead to a 4.1-day reduction in which URTI symptoms were reported. The average daily step count on days in which participants were healthy made up 43.5% (p<0.001) of the total number of days with recorded URTI symptoms. Children who spent more than 3 hours per week playing sport had less URTIs; however, this association accounted for just 4.0% of the variance in days with URTI symptoms.
Researchers reviewed the average daily steps (7,518) of participants on days when no URTI symptoms were reported, in order to understand potential lag between activity levels and risk of contracting URTI. The active group (n=47) had a mean of 9,368 steps during this ‘run-in’ period; the less active group (n=47) had a mean of 5,668 steps. The active group had less cumulative value of person-days with URTI infections (724 versus 947) over the following 46-day period, which exhibits the association between URTI and baseline physical activity levels. It was also concluded that sex, siblings, vaccinations, exposure to smoking or pet hair, and sleep duration were unrelated to the number of days with URTI.
Lead study author Katarzyna Ostrzyek-Przedziecka commented: “The recently observed displacement from a physically active lifestyle, and the refrainment from a natural outdoor environment in all segments of the human population… has led to a sedentary indoor lifestyle due to excessive use of modern technology, and may be reflected in chronic diseases that are endemic to our culture.”