Need another motivator to get in shape? Bouts of exercise and sex may be riskier to your heart if you're inactive, research suggests.
An analysis in this week's Journal of the American Medical Association of 14 previous heart studies suggests irregular physical activity can be a trigger for a heart attack or unexpected death, and infrequent episodes of sexual activity increases risk for just heart attacks. No studies examined the association of sex and sudden cardiac death.
About 1 million heart attacks and 300,000 cardiac arrests occur in the USA a year, the study says.
Researchers found a 3.5 times increased risk of heart attack from episodic physical activity, and sex was associated with a 2.7 times greater risk.
The study is a careful review and updates established data, says Joseph Marine, associate professor of medicine at Johns Hopkins University School of Medicine in Baltimore. It "emphasizes that sudden, out-of-the-ordinary levels of exertion in the otherwise sedentary person may be associated with heart attack," he says. "Like an older person who does very little exercise, then snow falls and they're out there shoveling."
Still, because episodes of physical exertion and sexual activity are infrequent and the risk increase short-lived, the absolute risk from these activities is small, notes lead author Issa Dahabreh, a research associate at Tufts Medical Center.
"It's not surprising to us cardiologists," says Irving Herling, director of consultative cardiology at The Hospital of the University of Pennsylvania in Philadelphia. He says inactive people tend to also have other risk factors for heart disease, such as smoking and obesity.
The message isn't to stop exercising or having sex, Herling and the study's authors say. And the paper doesn't take into account the overall beneficial effect of physical activity on heart health, which has been established in other large studies, Dahabreh says.
"Walking, any kind of physical activity on a routine basis -- risk is reduced substantially even by doing that," Herling says. "I mean, people will go around for half an hour looking for the closest (parking) spot to the gym, but that's the mentality of our world."
To see more of USAToday.com, or to subscribe, go to http://www.usatoday.com
Copyright 2011 USA TODAY, a division of Gannett Co. Inc.