▶ Proof of vaccine-like effect, maximum effect in 150 minutes per week
▶ Avoid excessive exercise such as obesity, diabetes and heart disease
During cold and flu season, the best way to stay healthy is to stay physically active. The correlation between regular exercise and better immune defense against disease, long considered folk wisdom, is supported by data from scientists who have been studying the risk factors for COVID-19. A review of 16 studies that studied physical activity during the pandemic found a causal relationship between exercise and the infection and severity of COVID-19. A recent study published in the British Journal of Sports Medicine is expected to provide the latest guidance for physical activity and health care policies. Experts say this study shows the importance of exercise in maintaining health.
▲ Exercise strengthens the immune system in different ways.
For decades, scientists have noted that healthy, physically active people are less likely to catch many respiratory infections. People who exercised tended not to be seriously ill when they fell ill. “Exercise reduced the risk of serious illness and death from the common cold, influenza (flu), and pneumonia,” said Dr. David Nieman, professor of health and exercise sciences at Appalachian State University. This can be said to have the same effect as a vaccine.”
A new meta-analysis examining studies between November 2019 and March 2022 shows that these effects extend to COVID-19. People worldwide who exercised regularly had a 36% lower risk of hospitalization and a 43% lower risk of death from COVID-19 compared to those who were less active. In addition, the risk of infection with the coronavirus was very low. Those who followed guidelines recommending at least 150 minutes of moderate physical activity or 75 minutes of vigorous activity per week benefited the most. Also, even those who exercised less than this were less likely to get sick than those who did not exercise at all. According to Dr. Niemann, the levels of cytokines (immune regulators) and immune cells decrease 2 to 3 hours after stopping exercise. However, he explained, if you exercise every day, your immune system becomes more responsive and can catch pathogens more quickly.
▲ Exercise magnifies the effects of some vaccines
The study also showed that exercise can increase the effects of some vaccines. For example, people who exercised properly after receiving the COVID-19 vaccine appeared to produce more antibodies. And in a study of older adults who were vaccinated early in the flu season, those who exercised had antibodies throughout the winter. “Exercise helps to reduce the number of cases and the severity of the disease,” said Dr. Stuart Ray, an infectious disease specialist at the Johns Hopkins School of Medicine.
Walking, jogging, going to the gym, or doing your favorite sport as a routine is known to reduce obesity, diabetes and heart disease. Dr Ray explained that exercise reduces the risk of getting the flu and COVID-19, improves sleep quality, improves mood, improves insulin metabolism and cardiovascular health. However, he added that it was difficult to know whether these effects were due to direct changes in the immune system or simply to better health in general.
Dr Peter Chin-Hong, an infectious disease specialist at UC San Francisco, pointed out that scientists need more research before they can identify a specific mechanism or causal relationship, and it is not good to put too much faith in the results of studies on exercise and strengthening immunity.
▲ Excessive exercise can make you more susceptible to disease
“There is a big debate about whether excessive exercise makes you more susceptible to infection and disease,” said Dr. Richard Simpson, who studies exercise physiology and immunology at the University of Arizona. Dr. Simpson reports that marathon runners often feel sore after a race, and some researchers believe that overly vigorous exercise can inadvertently overstimulate cytokines and inflammation in the body. In particular, non-stop exercise depletes the body’s glycogen stores, which in some people can lead to reduced immune function for hours or days, depending on their underlying health.
In addition, group exercise or participation in vigorous sports training camps increases the likelihood that athletes will be exposed to more pathogens. Other experts say that people who are physically active are less susceptible to infection simply because they can track their health more closely. “It is true that exercise can help prevent serious illness, but there is no need to despair for those who have difficulty getting moderate exercise or who for some reason are unable to exercise at all,” he advised Dr. Ray.
Eunseon Ha Reporter >
