High blood pressure, which affects nearly 50 million
Americans, is a serious public health challenge for
the United States (1). Cardiovascular disease has been
the leading cause of death in the United States for more
than 80 years. It is estimated that more than $320 billion
is spent annually on the approximately 60 million
Americans with cardiovascular disease, for which high
blood pressure is an important modifiable risk factor (2).
Epidemiologic studies indicate that uncontrolled elevated
blood pressure leads to stroke, coronary heart disease,
congestive heart failure, and end-stage renal disease
(3). Clinical trials have demonstrated that lowering
blood pressure reduces incidence of and death from cardiovascular
disease (3, 4). These studies also indicate
that a decrease of as little as 2 mm Hg in mean diastolic
blood pressure in the general population could substantially
reduce the risk for disease associated with elevated
blood pressure (5).
Physical inactivity is a major risk factor for cardiovascular
disease, and persons who are less active and less
fit have a 30% to 50% greater risk for high blood pressure
(2). Several recent clinical trials have demonstrated
that physical activity reduces blood pressure in hypertensive
and normotensive persons, independent of
weight loss (6–9). However, evidence regarding the
magnitude of exercise-related reductions in blood pressure
is inconsistent, both in general and among subgroups
of the population. Pooling results from individual
clinical trials provides more precise and accurate
information on the effect of aerobic exercise on blood
pressure and allows exploration of variation in intervention
effect among subgroups of interest.