Does air pollution reduce the effectiveness of exercise for patients with heart disease?

This study examined if high air pollution reduced the effectiveness of exercise for patients with heart disease. The authors found that moderate to intense exercise reduced patients’ risks of heart disease and strokes regardless of air pollution.

Exercise is one way that patients can reduce their risks of heart disease or complications arising from heart disease. Air pollution can affect patients’ health and increases the risks of heart disease. It is unclear if the effects of air pollution reduce the effectiveness of exercise when completed outside.

189,771 adults aged 40 or older completed a questionnaire on type and frequency of exercise and air pollution in their area was measured. Patients were divided into those who exercised intensely or moderately and by frequency (over 5 days per week or less).

Patients who frequently completed an intense exercise in high air pollution were compared to those who did not exercise and had little exposure to pollution. Patients who exercised had a 27% lower risk of heart disease than those who did not. Patients who exercised also had a 24% lower risk of heart attacks than those who did not. The risk of strokes was 30% lower in patients who exercised.

Patients who frequently completed a moderately intense exercise in high air pollution were compared to patients who did not exercise and had little exposure to air pollution. Patients who exercised had a 16% lower risk of heart disease and a 20% lower risk of heart attacks. Exercise also reduced the risk of strokes by 14%.

Patients who frequently completed intense exercise in low air pollution were compared to those who did not exercise. Exercise reduced the risk of heart disease by 38% and strokes by 48%.

Patients who frequently completed a moderately intense exercise in low air pollution were compared to patients who did not exercise. Patients who exercised had a 26% lower risk of heart disease and a 32% lower risk of stroke.

The authors concluded that frequent exercise reduced patients’ risks of heart disease, heart attacks, and strokes regardless of air pollution levels.

Patients’ exercise routines were described by questionnaires and may not be accurate. Air pollution levels were roughly calculated using data from the geographic area and also may not be accurate. This study was conducted in South Korea and may not reflect results or pollution levels in other areas in the world.