Owning car, TV linked to heart attacks: study

More broadly, the study -- covering more than 29,000 people in 52 countries -- showed that working up a light sweat may be the best preventative medicine against heart failure.

Until now, surprisingly little research has focused on how physical exertion at work and play influences the incidence of heart attacks, and even less has directly compared this data across nations at all income levels.

"This study shows that mild to moderate physical activity at work, and any level of activity during leisure time, reduces the risk of heart attacks," said lead researcher Claes Held, a professor at Uppsala University in Sweden.

It also "extends previous findings of the protective effect of leisure-time physical activity ... to low- and middle-income countries."

Held and colleagues poured over data collected from 1999 to 2003 for the so-called Interheart study.