Why smog should not be your excuse to skip workouts

 

Even when traffic fumes permeate the air, it’s still better for your heart if you get outside and exercise than if you spend all day sitting inside, a recent study suggests.

While exercise has long been linked to a variety of health benefits including a reduced risk of cardiovascular disease, exposure to air pollution has been tied to an increased risk of heart attacks, asthma and chronic obstructive pulmonary disease (COPD), lead study author Nadine Kubesch of the University of Copenhagen in Denmark said in a statement.

For the study, Kubesch and her colleagues examined data on air pollution exposure, exercise habits, and hospitalizations or fatalities related to heart attacks for 51,868 adults in Denmark ages 50 to 65. During an average follow-up period of almost 18 years, 3,260 participants, or 6 per cent , had either a first or recurrent heart attack.

People living in areas with high levels of air pollution were 17 per cent more likely to have a heart attack during the study than residents of low-pollution areas, the study found. And those who had a history of heart attack at the start of the study were 39 per cent more likely to have a heart attack during follow-up when they lived in high-pollution areas.

Exercise, however, appeared to help even when people lived in polluted places. Adults who regularly played sports in regions with high levels of air pollution, for example, were 21 per cent less likely to have a heart attack than people who were inactive.

“Our study shows that physical activity even during exposure to air pollution . . . can reduce the risk of heart attack,” Kubesch said in a statement. “Our research supports existing evidence that even moderate levels of regular physical activity, such as active commuting, are sufficiently intense to get these health benefits.”

The researchers looked at sports, cycling, walking and gardening and found all of these activities, except taking a stroll, associated with a lower risk of heart attack.

Among people who already had a history of heart attack, cycling, gardening and walking were all associated with a lower risk of a repeat episode.

It didn’t take much to make a difference, either.

Compared with people who got less than a half hour per week of any physical activity, those who got anywhere from a half hour to four hours of exercise were 23 per cent less likely to have a first heart attack and people who worked out more than four hours had 28 per cent lower risk.

When researchers looked only at outdoor physical activity, a half hour to four hours per week was associated with a 19 per cent lower first heart attack risk and more than four hours was linked to a 24 per cent lower risk.