Walk Away from High Blood Pressure
Surely everyone knows by now that regular exercise is vital in helping to prevent or control high blood pressure (hypertension). How much and how often, though, are questions that have been the subject of speculation and more than a few studies. Now comes one from the department of kinesiology at Indiana University and Indiana University Medical Center, Bloomington, with results that surprised even the study authors.
Researchers wanted to find out which is better for reducing prehypertension -- continuous physical activity, in this case walking, or walking that totaled the same amount of time but was performed in short spurts.
Prehypertension is blood pressure that runs from 120 to 139 mmHg (systolic) over 80 to 89 mmHg (diastolic), which are under the official level of hypertension. They discovered that 40 minutes of walking, whether in one continuous outing or in frequent spurts for shorter periods of time, reduced blood pressure by a similar amount compared with control subjects (a 5.4 to 5.6 drop in systolic pressure, and a 3.1 to 3.4 drop in diastolic pressure). However, when the group took shorter, more frequent walks (four times a day, in this study) the effect lingered for 11 hours, versus only seven hours when the group performed continuous walking.
I called the study's co-author, Janet P. Wallace, PhD, who assured me that both exercise groups did identical "work" (intensity) -- whether it was continuous or broken up throughout the day. Participants walked at 50% of their capacity (or VO2 max, a measure of aerobic fitness), which is a moderate pace. "Brisk" walking is working at 70% of capacity, she says, but in treating blood pressure with exercise, the ideal is moderate intensity and longer duration -- 45 minutes is optimal and one hour is max, according to Dr. Wallace, since after an hour there is no further measured short-term benefit. (Anything over 60 minutes is affected by the law of diminishing returns... you do not get that much more out of working longer, she said.) I wondered if part of the reason for the longer effect was the chance to relax several times a day, but Dr. Wallace says it more likely results from spreading out the physical stimulus over a longer period.
Her advice, based on the study, is to do whatever fits best into your life -- continuous or several briefer periods of activity in the day. And there's nothing magical about walking (other than how easily it can be done)... any kind of moderate intensity physical activity helps keep blood pressure down, she says. In a previous study her team discovered that even gardening and housework were helpful. The key is finding and doing activities that are easy for you to accomplish, and that you will do every day, be it 45 minutes on the treadmill at the gym or getting out of the house or the office every few hours for short walks outside.

Source(s): Janet P. Wallace, PhD, professor, department of kinesiology, Indiana University, Bloomington, Indiana.