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Pollution Can Cancel Out the Health Benefits of Walking for Exercise

The good, the bad and the ugly things we learned about our bodies today

A brisk walk outside has long been considered an important, if not an underrated, form of exercise, especially for people with injuries or weight issues. Here’s Fitness Magazine promising that you could lose up to 10 pounds a month just by putting a little pep in your step.

And, if you live in the suburbs or the country, that’s true. But if you’re a city slicker aged 60 or older, you’d best take that workout indoors onto a treadmill. That’s because a disturbing new report suggests that all that hard work you’ve been putting in, high-stepping around your neighborhood, is being undone by an invisible-ish evil: Pollution.

Researchers at Duke University and Imperial College in London have found that even short-term exposure to traffic exhaust in a big city can cancel out the positive effects of a long walk.

Participants in the study were asked to split up into two groups, one that paced around a park and another on a high-traffic street, both for a period of two hours. Researchers observed that the group that walked in the park saw noticeable improvement in lung capacity that lasted as long as 24 hours after the walk finished, while the group that made their way through the city streets saw no measurable improvements whatsoever.

“Combined with evidence from other recent studies, our findings underscore that we can’t really tolerate the levels of air pollution that we currently find on our busy streets,” explained Fan Chung, professor of respiratory medicine at Imperial College’s National Heart & Lung Institute.

Chung and his co-author Jim Zhang, professor of global and environmental health at Duke, hope their study will help convince city leaders around the world to take green spaces more seriously in city planning, as well as the importance of tougher fuel restrictions for cars. After all, cardio and car exhaust should never go hand in hand.

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