These studies have documented that the duration of
exercise does not play a significant role in determining
the occurrence or the magnitude of PEH. The
initial study indicated that each of 15, 30 and
45 min of cycle ergometry at 70% V·
O2 Peak elicit a
similar hypotensive response in healthy young men.
The second study found that 10 min of exercise is
also sufficient to cause PEH. This is contradictory to
earlier work by Bennett et al,
4 who suggested that,
as the duration of the exercise increased, so did the
magnitude of the hypotension. In their study, postexercise
blood pressure was measured during a 3-
min rest period between 10-min bouts of exercise,
thus making it difficult to compare their data with
those of the present study. We did, however, observe
in both of the present studies that blood pressure
was more stable or still declining at the end of the
1 h measurement period following the longer duration
of exercise (ie, 45 min in study 1 and 30 min in
study 2) whereas it was increasing after the shorter
exercise bouts. Thus, it is possible that the duration
of exercise may affect the duration of the hypotension.
Further work will be needed to investigate
this possibility.
Our findings lend support to the numerous studies
that have found PEH to occur following a variety
of exercise durations6–10 and suggest that moderate
intensity exercise of relatively short duration (ie,
10 min) is sufficient to evoke a hypotensive
response.
A number of previous studies have indicated that
PEH does not occur in a normotensive population.5,8–10,13
The initial investigation here, as well
as previous work from our laboratory6 has shown
that normotensive individuals do experience decrements
in resting pressure after an acute bout of
exercise. However, subjects in study 2 of the present
investigation had higher resting blood pressure and
the magnitude of their post-exercise hypotension