The scientists found that as children's physical activity increased, their susceptibility to experiencing respiratory symptoms decreased.
It's common knowledge that physical activity is critical for health and wellbeing — even for children. However, recent research reported that three out of four teens aren’t getting enough exercise.
Now, a new study found that children who don’t engage in a healthy dose of physical activity may be more likely to get a respiratory illness.
The research, published in Pediatric Research on January 24, measured physical activity and tracked respiratory symptoms in 104 Polish children between the ages of 4–7 years between 2018 and 2019.
The children wore an armband that recorded their sleep duration and activity levels 24 hours a day for 40 days. Also, using daily questionnaires, parents noted any respiratory symptoms in their children, like coughing or sneezing.
In additional surveys, the parents reported on other aspects of their child’s life, including vaccinations, sports participation, and exposure to pet hair or smoking.
After analyzing the data, the team found that children with higher activity levels at the beginning of the study also had fewer respiratory infection symptoms during the next six weeks.
For example, among 47 children who averaged 5,668 steps per day during the first two weeks of the research, the total number of days they experienced upper respiratory symptoms during the following six weeks was 947.
In contrast, among 47 children who averaged 9,368 steps per day in the study’s initial weeks, the combined total number of days they had respiratory symptoms during the following six weeks was 724.
The authors also found that with every daily 1000-step increase, the number of days experiencing respiratory symptoms decreased by an average of 4.1 days.
Moreover, children who were active in sports three or more hours a week appeared to experience fewer respiratory infection symptoms than those that did not play sports.
In addition, the scientists found no associations between upper respiratory tract infection symptoms and sleep duration, number of siblings, vaccinations, or exposure to pet hair or smoking.
The study authors suspect that higher levels of exercise may reduce inflammatory cytokines and promote immune cell function. They also hypothesize that physical activity could help the muscles release specific immune modulators. However, more research is needed to identify the potential immune-modulating mechanisms exercise promotes in children.
Still, they stress that because of the observational nature of their investigation, they cannot determine conclusively if high physical activity causes less susceptibility to respiratory infections in young people.