of a decrease in peripheral vascular resistance (as cited
above), even though there was an increase in renin activity,
persistent sympathetic activity and reduced vagal tone, possibly
due to peripheral vasodilatation.
Neural and humoral factors also influence BP levels.
Reductions in cardiac output and decreases in peripheral
vascular resistance are associated with the occurrence of
PEH40, 41)
. Two mechanisms have been proposed for explaining
the post exercise decrease of peripheral resistance:
sympathetic inhibition, and alterations in vascular responsiveness.
The activation of the neurokinin-1 receptor during
exercise triggers the receptor to undergo internalization
after the completion of exercise, dampening the GABA interneurons
solitary tract nucleus, and modifying the baroreflex
to a lower level after exercise, by reducing transmission
to baroreceptor second-order neurons, increasing the
excitement of the ventral caudal lateral medulla, increasing
inhibition of the rostral ventral lateral medulla, inhibiting
its action, and decreasing sympathetic nervous activity,
leading to post-exercise hypotension. On the other hand, a
greater local release of nitric oxide, prostaglandins, adenosines,
and ATP may also alter the vascular response and
contribute to BP reduction42)
.
T2D patients can present endothelial dysfunction2) and
reduced release of vasodilator substances, which suggests
that a possible mechanism for the decrease of vascular resistance
is damaged in this population, as observed in the
post-MOD response. Nevertheless, after MAX this limitation
would be less evident, as was demonstrated in the present
study of T2D patients. Perhaps exercise performed at
higher intensities allows greater recruitment of motor units
and, consequently, induces greater metabolic and hemodynamic
stress, as well as promoting greater BP decrease in
the post-exercise period.
The American College of Sports Medicine9) recommends
moderate intensity exercise for individuals with
T2D, but higher intensity exercise may have additional
benefits for cardiorespiratory fitness and glucose control44)
.
Maximal exercise is a very well known and useful method
for verifying exercise response. Thus, its use is important
for determining the response of special populations such
as T2D patients, considering that these individuals tend
to present more cardiovascular problems5)
. Nevertheless,
it is important to point out that the use of high intensity
exercise with T2D patients should be well supervised, and
performed only by individuals whose BP and T2D are controlled
and who have no associated complications such as
cardiovascular dysfunction, and should be used only after
having proven the patient’s physical and cardiorespiratory
fitness in clinical examinations.
Finally, we conclude that a single aerobic exercise session
resulted in BP reduction for 24 h in individuals with
T2D, particularly while sleeping, and the magnitude of this
reduction seems to be dependent on the intensity at which
the exercise is performed.