You may have heard the advice. One of the best things you can do to stay healthy, especially with cold and flu season looming, is to keep moving.
This folk wisdom has been around for years, but until recently, researchers didn’t have much data to support this idea. Scientists have revealed some preliminary evidence for a link between regular exercise and better immune defenses against disease.
Researchers reviewed 16 studies of people who remained physically active during the pandemic and found that working out was associated with a lower risk of infection and a lower likelihood of becoming seriously ill. Published in the British Journal of Sports Medicine, has generated much enthusiasm among exercise scientists. They say the findings could lead to updated guidelines for physical activity and health care policies centered around exercise as medicine.
Experts who study immunology and infectious disease are cautious about interpreting results. However, they agree that exercise helps protect health through several different mechanisms.
Exercise may boost immunity
For decades, scientists have observed that healthy, physically active people appear to have lower rates of some respiratory infections. David Niemann, a professor of health and exercise science at Appalachian State University, who was not involved in the study, said that when people who exercise get sick, they tend to be less severe. The risk of severe outcomes and death from colds, flu, pneumonia — they’re all pretty much knocked down,” Professor Niemann said. “I call it a vaccine-like effect.”
A new meta-analysis looking at studies from November 2019 to March 2022 finds this impact extends to Covid. People around the world who exercised regularly had a 36% lower risk of hospitalization and a 43% lower risk of dying from Covid compared to inactive people. Totally low.
People who followed guidelines recommending at least 150 minutes of moderate activity or 75 minutes of vigorous activity per week seemed to benefit the most. However, even those who exercised less were more protected from disease than those who did not exercise at all.
Researchers theorize, for example, that exercise may help fight off infectious bacteria and viruses by increasing the circulation of immune cells in the blood. , also found that muscle contractions and movements release signaling proteins known as cytokines that help immune cells find and fight off infections.
Even if levels of cytokines and immune cells taper off a few hours after you stop exercising, your immune system is more responsive, says Niemann, and if you exercise every day, you’ll kill pathogens faster over time. you can catch it. “Your immune system is primed and ready to fight any viral load,” he said.
In healthy people, physical activity is also associated with a reduction in chronic inflammation. Widespread inflammation can even turn your own immune cells against your body, which can be very damaging. According to Professor Niemann, this is a known risk factor for Covid. So it makes sense that reducing inflammation would increase your chances of fighting off an infection, he said.
Studies also show that exercise may amplify the benefits of some vaccines. And in a study of older adults who were vaccinated early in the flu season, those who exercised had sustained antibodies throughout the winter.
Stuart Ray, M.D., an infectious disease specialist at Johns Hopkins University School of Medicine, says exercise offers a number of broad health benefits that may help reduce the incidence and severity of disease. Incorporating walking, jogging, gym trips, or sports into your routine is known to help reduce obesity, diabetes, heart disease, and more. These are all risk factors for severe influenza and novel coronavirus. Exercise can help you get more restful sleep, boost your mood, improve insulin metabolism and cardiovascular health, and increase your chances of getting the flu and COVID-19. According to Dr. Ray, it’s difficult to know if the benefits are due to direct changes in the immune system or simply an improvement in overall health.
Research can only tell us a lot
Dr. Peter Chinghong, an infectious disease specialist at the University of California, San Francisco, agreed that more research is needed before scientists can identify specific mechanisms or causal relationships. said it’s important not to believe it too much. “Right now, you can’t say, ‘I’m going to the gym to prevent catching Covid,'” Dr. Chin-Hong said. The problem with studying the exact effects of obesity on immunity is that exercise isn’t something that scientists can easily measure on a linear scale, Dr. Ray said. increase.”
Research participants typically self-report the amount and intensity of their exercise, which can often be inaccurate. And even just expecting exercise to be beneficial can have a strong placebo effect. there is. It’s also quite possible that people who exercise regularly share other attributes that help fight infections, such as better access to different diets and health care, he said. Stated.
“There’s a lot of debate about whether too much exercise makes you more susceptible to infections and illnesses,” said Richard Simpson, who studies exercise physiology and immunology at the University of Arizona.
Marathon runners often feel sick after a race, Simpson said, and some researchers believe that exercising too hard can inadvertently overstimulate cytokines and inflammation in the body. Exercising without breaks depletes the body’s glycogen stores and can compromise immune function for hours or days, depending on baseline health. Attending sports training camps may expose athletes to more pathogens. Other experts point out that physically active people may simply track their health more accurately.
Still, there is early evidence that it may have a protective effect for the average exerciser. But those who have trouble getting enough exercise, or who for whatever reason are unable to exercise at all, should not despair. is a complex combination of many factors,” he said. – This article was originally new york times
