The Journal of the American Medical Association examined 14 previous heart studies that suggested 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.
About 1 million heart attacks and 300,000 cardiac arrests occur in the USA a year.
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. They compared the results akin to an older person who does very little exercise, then snow falls and they're out shoveling.
Cardiologists say that 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. It is really about getting physical activity on a routine basis so you don't shock your body when you decide to be active out of the blue.