If you have older-adult clients or class participants who are afraid to exercise because of mild high blood pressure, a Johns Hopkins study may ease their concerns. Research results on 104 men and women ages 55–75 showed that a moderate program of physical exertion had no ill effects on the heart’s ability to pump blood, nor did the activity produce a harmful increase in heart size. Researchers say that people’s concerns about exercise stem from the fact that blood pressure levels can rise from 40 to 60 millimeters of mercury, on average, during each workout. In this study, “moderate” meant a subject could sustain exercise for about an hour three times a week.

A report on the study, published in the July issue of the journal Heart (2006; 92, 893–98), showed that after 6 months of cardiovascular exercise on a treadmill, a bicycle or a stepper, in addition to strength training, participants showed no overall ill effects in 11 measures of diastolic heart function. Researchers also found that exercise did not cause an increase in eight measures of heart size. In contrast, one long-term effect of hypertension, even when the body is relaxed, is hypertrophy, an enlargement of the heart that eventually stiffens and weakens the muscle.

“While having high blood pressure at rest is a well-established risk factor for heart problems, older people should not fear the effects of moderate exercise on the heart, despite short-term bump-ups in blood pressure during their workout,” said lead study investigator Kerry Stewart, EdD, professor of medicine and director of clinical and research exercise physiology at The Johns Hopkins University School of Medicine and its Heart Institute, in a press release. “Exercise is a highly effective means of increasing the heart’s efficiency and reducing body fat, factors that may ward off future health problems, such as heart disease and diabetes.”