Is sex bad for the heart in older men ... or good?

Men with cardiovascular disease often wonder whether sexual activity might be dangerous for them, potentially triggering a heart attack in the midst of the excitement, or whether the exercise might actually be good for the heart. A new review by the Harvard Men’s Health Watch indicates that, as exercise, sex is probably not very helpful, but it is also most likely not very dangerous either.

Careful studies have shown that about one in every 100 heart attacks is related to sexual activity; for fatal arrhythmias, the rate is about one in 200. For a healthy 50-year-old man, the risk of having a heart attack in any one hour is about one in a million; sexual activity doubles the risk, but that risk is still just two in a million. For men with heart disease, the risk is 10 times higher, but that is still only 20 in a million, comfortingly low.

As exercise, however, sex falls short. Researchers studied 19 men, measuring their heart rate and other vital functions on a teadmill in the laboratory and having sex in the privacy of their home. During sex, their heart rate increased by only about 72% as much as it did on the treadmill, and blood pressure was only 80% as high. On an intensity scale of one to five, men evaluated treadmill exercise as 4.6 and sex as 2.7. Sex was even less strenuous for women. In terms of oxygen consumption, another measure of the vigor of the activity, sex rated about the same as doing a fox trot, raking leaves or playing ping-pong. Sex burns about 5 calories per minute, about the same as walking on a golf course.

Sex may even protect the heart, according to at least one study. Results from the Massachusetts Male Aging Study, the review said, found that men who had sex less than once a month were 45% more likely to develop cardiovascular disease than those who had sex two or more times a week. But the researchers also cautioned that the men who had sex infrequently may also have been burdened by social isolation or smoking, drug abuse, or diseases that impair libido and potency.

Erectile dysfunction drugs such as Viagra, Levitra and Cialis do not increase the risk, the review found, but men should not take the drugs if they are taking nitrate-containing drugs for their heart disease. Such drugs include nitroglycerin; long-acting nitrates; nitroglycerin sprays, patches and pastes; and amyl nitrate.