The risk of death in older adults fluctuates based on the intensity of exercise, even when exposed to the same fine dust concentration, a recent study from Severance Hospital showed.

Led by Professor Joung Bo-young from the cardiology department at Severance Hospital, along with Park Han-jin, a cardiology lecturer at Severance Hospital, and Professor Yang Pil-sung from the cardiology department at CHA Bundang Medical Center, a research team examined the correlation between fine dust concentration and exercise intensity among individuals aged 65 or older. The findings indicated that both moderate and high-intensity exercise demonstrated positive effects on longevity, particularly in areas with low dust concentrations.

Physical activities can be classified into two main categories: moderate exercise, which includes activities like walking and bicycling, and high-intensity exercise, such as vigorous running that may lead individuals to experience breathlessness.

Physicians often discourage outdoor exercise during periods of poor air quality, as fine particulate matter poses a risk of causing cardiovascular and respiratory issues.

Nevertheless, studies have not identified specific effects of exercise intensity on the body, even when considering the same level of air quality.

Leveraging data from the National Health Insurance Service, the researchers examined the impact of annual average Particulate Matter 10 (PM10) concentrations and exercise intensity on the longevity of 81,326 individuals aged 65 and older. These participants consistently engaged in a minimum of 30 minutes of physical exercise per week, spanning from January 2009 to December 2012.

The findings showed that both moderate- and high-intensity exercise in low-pollution areas with annual average particulate matter concentrations of 54.5 μg/m³ (cubic micrometers, top 10 percent nationally) or less have a positive impact on longevity.

Of the total amount of exercise in older adults, a 10 percent increase in moderate exercise was associated with a 2.3 percent reduction in mortality risk and a 10 percent increase in high-intensity exercise resulted in a 2.8 percent reduction in mortality risk.

Nevertheless, in instances where the average annual PM10 exceeded 54.5 μg/m³, the risk of death varied based on exercise intensity. A 10 percent increment in moderate exercise lowered the risk of death by 4.8 percent among older adults in regions with elevated concentrations of fine dust. In contrast, increasing the proportion of high-intensity exercise by the same magnitude raised the risk of death by 4.9 percent.

"This study confirms that the presence of fine particulate matter does not necessarily prevent people from exercising outdoors," said Professor Joung . "However, we recommend that high-intensity exercise should be done indoors when air quality is poor due to high concentrations of fine particulate matter."

The findings were published in the latest issue of the Mayo Clinic Proceedings, titled "Association Between the Combined Effects of Physical Activity Intensity and Particulate Matter and All-Cause Mortality in Older Adults".