NEW RESEARCH SUGGESTS that that spikes in physical activity – including sex – increase the risk of heart attacks in people who do not regularly engage in exercise.

The intense cardiovascular nature of sex can put strain on the hearts of those who are not, ahem, regular practitioners. If you are not used to strenuous exercise, your risk of myocardial infarction (heart attack) goes up 2.7 times during “episodic activity” such as sex, the study in the Journal of the American Medical Association reports.

“Anecdotal evidence has suggested that physical activity, as well as other acute exposures, such as sexual activity and psychological stress, can act as triggers of acute cardiac events,” the study authors wrote, with people being most at risk one to two hours after the activity has ceased.

For people who are reasonably fit however, sex and other exercise actually reduces the risk of  heart attack. 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.

Regular physical activity has been identified as strongly associated with a decreased risk of cardiovascular disease and related mortality.

Dr Robert Ostfeld, associate professor of clinical medicine at Montefiore Medical Centre in New York City, was quoted in Businessweek as saying the message of the study is to exercise sensibly.

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.