BOSTON, MASSACHUSETTS. Many studies have shown that regular, vigorous exercise reduces the risk of coronary heart disease in both men and women. What is less clear is just how vigorous the exercise has to be in order to confer significant benefits.
Researchers at the Brigham and Women's Hospital and the Harvard Medical School
have just published the results of a study designed to clarify this question.
Their study involved 39,372 healthy female health professionals aged 45 years or
older who were enrolled between September 1992 and May 1995 and followed up to
March 1999. At the end of the study period 244 cases of coronary heart disease
had been diagnosed. The researchers found a clear protective effect of even
walking at a moderate pace for at least one hour per week. Women who did this
had a 50 per cent lower risk of developing coronary heart disease than did women
who did not walk regularly. The pace of walking was less important than the
time spent in walking and increasing pace or walking time (beyond 1.5 hour/week)
did not provide added protection. The benefits of regular walking were
particularly pronounced among present and past smokers. The researchers
conclude that their work supports current guidelines for heart disease
prevention, which calls for moderate-intensity physical activity for 30 minutes
per day most days of the week.