The long-term study, which lasted 15 years, was focused on 384,130 adults in Taiwan. The researchers set out to quantify the effects of regular exercise among individuals exposed to fine, airborne particulate matter on relation to the risk of premature death.
The experts found that, although reducing exposure to air pollution was the ideal situation, people who took part in regular exercise decreased their risk of premature death, even in polluted areas.
“Habitual exercise reduces the risk of death regardless of exposure to air pollution, and air pollution generally increases the risk of death regardless of habitual exercise,” wrote the study authors, including Dr. Xiang Qian Lao of the Jockey Club School of Public Health and Primary Care at the Chinese University of Hong Kong.
“Thus, habitual exercise should be promoted as a health improvement strategy, even for people residing in relatively polluted areas.”
The research showed that a reduced risk of death from natural causes was associated with both lower levels of air pollution and higher levels of regular exercise. By contrast, greater inactivity and high levels of exposure to air pollution correlated with an increased risk of death.
The study supports other, smaller studies from the United States, Denmark and Hong Kong which found regular exercise to be beneficial, even in polluted areas.
“Further studies in areas with more severe air pollution are required to examine the applicability of our findings,” said the researchers.
“Our study reinforces the importance of air pollution mitigation, such as to reduce the harmful effects of air pollution and maximize the beneficial effects of regular exercise.”
In a related commentary, also published in the Canadian Medical Association Journal, experts at the Sydney School of Public Health said they consider physical inactivity and air pollution to be “syndemics,” meaning these two health problems interact synergistically and produce an excess burden of disease.
Furthermore, safety recommendations such as exercising indoors or avoiding running and cycling on busy roads do not address the causes of the problem. In fact, since poor people may be unable to access these options, such recommendations can add to inequalities in health.
“Risk reduction approaches that do not address the root causes of noncommunicable diseases could exacerbate health inequalities,” explained the commentary authors. “People should not be forced to choose between physical activity and air pollution.”
“Both physical inactivity and air pollution have detrimental effects on health. Staying active should not be at the cost of compromised health from air pollution. Addressing both major public health issues through synergistic, upstream, system-level approaches would lead to long-term health benefits for humans and the planet.”