METHODS
Study Selection
We conducted a comprehensive literature search of
MEDLINE (1966 to September 2001) using the Medical
Subject Headings exercise, physical fitness, hypertension,
and blood pressure and the keywords physical activity
and aerobic exercise. We also searched the SPORTDiscus
database using the same strategy. In addition, we conducted
a manual search by examining reference lists
from original research papers and review articles. Initially,
three of the authors used predetermined selection
criteria to identify and independently review 104 original
research reports that included 121 trials. Disagreements
were resolved by discussion and, when necessary,
by deliberation with a fourth investigator. We included
studies that were published in English-language jour