TUESDAY, March 22, 2011 (HealthDay News) -- People who engage in physical activity only once in a while -- and that includes sex -- have a higher risk of suffering a heart attack or sudden cardiac death, at least in the one or two hours right after they've exerted themselves, experts say.
But in another nod for exercise, the more physical activity you engage in, sexual or otherwise, the more protected you are against such problems, according to a study in the March 23/30 issue of the Journal of the American Medical Association.
"The triggering effect appeared to be sharpest for people unaccustomed to physical activity," said study senior author Jessica K. Paulus, an assistant professor of medicine at Harvard School of Public Health and an adjunct assistant professor of epidemiology at Tufts Medical Center, in Boston. "The recommendation from our paper is consistent with current guidelines, that those looking to initiate an exercise program, especially those at higher risk, do so very gradually and under the care of a clinician or physician."
Certainly previous studies have looked at this issue, but most of those had been unable to pinpoint issues of timing, said study author Dr. Issa J. Dahabreh, a research associate with the Center for Clinical Evidence Synthesis, Institute for Clinical Research and Health Policy Studies at Tufts.
This meta-analysis took the weighted average of 14 other studies to determine that people who engaged in "episodic" sexual activity had a 2.7 times higher risk for a heart attack while sporadic physical activity raised the risk 3.5-fold.
Occasional physical activity raised the risk of sudden cardiac death fivefold, but overall risk was low largely because people engaged in these activities so infrequently and the risk went away so quickly.
"The actual incidence is extremely small. You're talking two-to-three events per 10,000 patient-years. That's very, very small," said Dr. Christopher Cove, an associate professor of medicine and assistant director of the cardiac catheterization lab at the University of Rochester Medical Center.
Also, the study found that each additional time a person exercised in a week reduced the risk for a heart attack by 45 percent and for sudden cardiac death by 30 percent.
"Exercising regularly is important because it can significantly decrease the risk," Cove added.
But whether or not sporadic physical or sexual activity actually causes heart problems is difficult to prove as more regular physical activity "could be a marker for overall good health," said Dahabreh.
"It's important to not lose sight of the message that exercise is the fountain of youth. This should not detract from that kind of thinking," said Dr. Robert Ostfeld, associate professor of clinical medicine at Montefiore Medical Center in New York City.
"The take-home message is that if you have not done much of any physical activity for a long period of time you should not go out and run a marathon tomorrow but build up more gradually, and that [once you've worked up to it] you should only exercise on the days you brush your teeth, which is hopefully every day," Ostfeld advised.
The American Heart Association has more on heart attacks.