Role of Physical Activity in the Prevention and Treatment of Influenza: A Review

Many concerns regarding respiratory diseases, including influenza, emerged during the epidemic of COVID-19. There were relevant research findings and suggestions for influenza prevention and treatment through physical activity, but little report about the total efficiency. So, this review was to summarize the role of physical activity in influenza prevention and treatment.

The databases Web of Science, Google Scholar, EBSCO, PubMed, CNKI, and Science Direct were used to search the related literatures. The first search ran from July to October, 2021, and the second search was conducted in September, 2023. Those publications that reported the effects of physical activity, exercise, and sport on influenza, flu, and cold were included. It found that long-term adherence to moderate physical activity is beneficial in enhancing the body's ability to resist influenza viruses. However, high-intensity endurance physical activity can cause an open window in the human immune system, which increases the risk of infection by influenza viruses. The patients with influenza infections can participate in moderate physical activity during the pre-onset period, but some of the researchers do not recommend physical activity for patients with influenza, avoiding the transmission of influenza viruses to others through human contact of physical activity. Moreover, animal studies have shown that physical activity may worsen influenza disease. While studies found that moderate physical activity is beneficial for preventing influenza, as most experimental studies were conducted on animals, the mechanisms in human with physical activity are still unclear. No study has yet suggested exercise prescriptions to prevent and control influenza, and there is currently no way to prevent or control influenza just through physical activity. The follow-up research is needed to increase human clinical experiments, elucidate the effect of physical activity on influenza, develop exercise prescriptions and gradually promote physical activity as a practical means for preventing and treating influenza.

Overall, participating in moderate physical activity regularly should be beneficial in influenza prevention, alleviating the patients' symptoms and increasing the recovery efficiency, but this needs more testing in clinical human trials.