The common problem reducing the benefits of your exercise
Better mental health, lower risk of heart disease and smaller waist are well-known health benefits of regular exercise.
But a new study suggests that some of the benefits of being active may be diminished depending on where you live. Scientists found that those who exercised regularly but were exposed to highly polluted air saw their death rates halved from exercise.
Research was conducted from University College London and published in the journal BMC Medicine Data from more than 1.5 million adults followed for more than a decade in countries including the United Kingdom, Taiwan, China, Denmark and the United States were analyzed. Adults’ exercise habits were tracked along with levels of tiny particles known as PM2.5, which can get trapped in the lungs and enter the bloodstream.
Researchers found that people who did moderate or vigorous exercise for at least two and a half hours a week had a 30 percent lower risk of death than those who didn’t.
However, if people in this group of very physically active people live in an area with high fine particle pollution (above 25 micrograms per cubic meter), this reduction in risk is halved to 12 to 15 percent.
The health benefits of exercise were further attenuated for those exposed to areas with higher levels of fine particle pollution. The researchers found that the benefits of exercise on cancer risk were “no longer robust” in those experiencing levels above 35 micrograms per cubic metre.
The team said almost half (46 percent) of the world’s population lives in areas where average annual PM2.5 levels exceed 25 micrograms of PM2.5 per cubic meter, and nearly a third (36 percent) lives in areas where annual average PM2.5 levels exceed 35 micrograms per cubic meter.
Average annual PM2.5 levels for study participants in the UK were below these thresholds of 10 micrograms per cubic metre. But researchers said levels of fine particle pollution were “very different” and “sudden increases” in pollution in UK cities could exceed 25 micrograms per cubic metre.
Lead researcher Professor Po-Wen Ku, from National Chung Hsing University in Taiwan, said the findings showed exercise in polluted environments was still beneficial, but improving air quality “could greatly enhance these health gains”.
The team added that the negative effects of air pollution can be reduced by “controlling air quality, choosing cleaner routes or easing congestion on polluted days.”
Co-author Professor Andrew Steptoe, from UCL’s department of behavioral science and health, said: “Our study shows that toxic air can inhibit, if not eliminate, the benefits of exercise to some extent. The findings are further evidence of the damage fine particle pollution can do to our health.”
“We believe that clean air and physical activity are important for healthy aging and therefore encourage greater efforts to reduce health-damaging pollution levels.”
This comes after a study found that even one minute of intense exercise a day can reduce your risk of premature death by 38 percent. Other studies have also shown that gender may have an impact on the benefits of exercise; One study concluded that men need about twice as much exercise as women to see the same reduction in heart disease risk.
