Ask the doctor

Are isometric exercises safe for the heart?

Q. Long ago I was told that isometric exercises, like weight lifting, shouldn't be done by anyone with a heart condition. Is that still the prevailing wisdom?

A. Isometric exercises are those in which a muscle tenses but doesn't contract. Clasping your hands together and pushing or lifting free weights are examples of isometric exercises. Physicians once discouraged people with heart disease from doing predominantly isometric exercises, like weight lifting and other resistance exercises, in part because they can lead to temporary but dramatic increases in blood pressure. Lifting weights is also thought of as an anaerobic exercise, one in which the body's demand for oxygen exceeds supply. The fear was that the combination of increased blood pressure and oxygen depletion might trigger a cardiovascular event like a heart attack.