Blood pressure in apparently healthy adults averages 120/80 mmHg or lower.  The top number, 120, represents the pressure against the artery walls when the heart contracts or systolic blood pressure.  The second number 80 is the pressure against the artery walls during the resting phase (between heart beats) and is termed diastolic blood pressure.  There are sensors throughout the body that regulate blood pressure and ensure it doesn’t fall too low or rise too high.  These mechanisms help keep adequate blood flow to tissues if blood pressure falls too low or conversely blood pressure doesn’t raise too high creating stress to the heart and vessels.  Generally, blood pressure rises and falls depending on the demands of the body.  Occasionally, blood pressure control mechanisms malfunction or are unable to compensate for the demands placed on the body.  One resulting condition is hypertension.

According to a study in the April 11 issue of Archives of internal Medicine (2005; 165[7], 756 – 62), moderate exercise may not be enough to control mild hypertension or high blood pressure in men and women over the age of 55.  The study took place over a six month period and involved both moderate cardiovascular and strength training activities.  A total of 51 exercisers and 53 controls completed the first trial.  All participants had untreated systolic or diastolic blood pressure.  Each of the exercisers performed prescribed exercises three times per week for a total of 90 minutes per session.  The control group maintained normal activities.

The conclusion of this study indicated that at the end of a six month period of aerobic and resistance training, diastolic BP (blood pressure) was lowered but not systolic BP in adults with mild hypertension.  It is an important finding, however, that exercisers showed a significant improvement in overall fitness and body composition over the control group.  The research found that those who lost the most body fat, especially abdominal fat, and gained the most muscle were the most likely to decrease both the systolic and diastolic blood pressure levels.  It is important to note that changes in body composition were more closely related to blood pressure reductions than to improved cardiac fitness.

According to Kerry J. Stewart, EdD, author of the study from The Johns Hopkins University School of Medicine, “They (patients) may also need to understand it could take much more time for them to reach blood pressure goals and it may require more intensive exercise programs.”

As indicated by the authors, the length of the study may have been a limiting factor in the reduction of blood pressure through exercise alone.  A study over a longer period of time may prove that exercise does indeed lower both systolic and diastolic blood pressures.  Our commitment to a healthier lifestyle should be life-long and not a reaction to a diagnosis we receive from our physicians at any given time in our life.  Exercise, as shown in this particular study, greatly effects body composition and does have an effect on diastolic blood pressure.  Abdominal fat can be indicator of increased risk of cardiovascular disease and metabolic disorders.

It is important to remember that the key to a successful exercise program is consistency overtime.  Don’t conquer the world the first time on the treadmill. Start gradually so that injury does not occur. As shown in this study, three times per week for ninety minutes was the dosage of exercise.  Many people do not have the time commitment or the fitness levels for these exercise parameters.  Also, these participants in this study were supervised. It is best to consult with a provider that is familiar with medical conditions and the appropriate exercise prescription for that particular individual.  You cannot cookie cutter an exercise program, especially for those with health concerns.

When we are younger, we assume our good health will last a lifetime.  As one ages, obligations to family and work take more of our time; our health takes a back seat. Remember our health is a commitment that should span our lifetime. 

- Donna Schneider, BS, CES, CPT, CEAS