So, yes, sex can trigger a heart attack. But the stats prove that you're more likely to suffer a cardiac event from road rage, shoveling snow or being the guest of honor at a surprise party.

Corroborating these findings, Swedish researchers interviewed the survivors of 699 heart attacks and found that only 1.3 percent had been triggered by sex. Not only that, the heart attacks clustered among the subjects who were least physically fit. The risk of sex-related heart attack is "very low," the researchers concluded.

Stateside researchers have contributed insights of their own: A Tufts University survey of 14 studies showed that sex-related heart attack risk is highest among those who are the least sexually active. For those who are more regularly sexual, the risk is barely "one per 10,000 person-years" — social science shoptalk for "minuscule."

When is it safe to resume sex after a heart attack? In Something's Gotta Give (2003), a 60ish heart attack survivor played by Jack Nicholson hopes to bed a successful playwright played by Diane Keaton. But something's sapping his mojo: Will his damaged heart, he wonders, be able to take the strain? His doctor (Keanu Reeves) advises him, "If you can climb a flight of stairs, you can have sex." Nicholson gazes longingly up a staircase outside Keaton's house, asking himself when he'll feel well enough to climb it again — and accomplish its sexual equivalent.

Next page: How you can avoid a heart attack during sex. »