148
Resistance ET, also called as strength training, is being increasingly prescribed
to patients with cardiovascular complications, from hypertensive to heart failure
patients. Indeed, several evidence have been demonstrating that resistance ET can
participate in conjunction with aerobic ET, or even alone, in the control of blood
pressure values in hypertensive patients [ 41 , 42 ]. Regarding MI, data from basic
research are still very limited.
In front of this lack in the literature, Grans et al. [ 19 ] subjected MI-rats to
12 weeks of low to moderate (40–60% of the maximum strength) resistance ET
program. After the resistance ET program, differences were not observed in the MI
size between the infarcted groups. Further analyses showed similar increase in left
ventricle mass and relative wall thickness – an indicator of scar formation – in
trained groups (i.e., non-MI and MI rats), with significant differences observed
between trained-infarcted and sedentary-infarcted rats, in favour of the trained
group. These data suggest a positive cardiac remodelling elicited by resistance ET
in MI rats. To verify whether data of cardiac function could corroborate with mor-
phological data and indicate a beneficial physiological hypertrophy after resistance
ET, the cardiac function was analysed. However, results did not demonstrate altera-
tions on ejection fraction [ 19 ]. Moreover, data demonstrate ameliorated autonomic
function, indicated by a decrease in both cardiac and vascular sympathetic modula-
tion, concomitantly with an increase in the parasympathetic modulation [ 19 ].
Therefore, more evidences regarding the effects of resistance ET on MI-induced
infarcted
heart
Cardiacremodelling
Cardiacfunctioning
ROS ̄Antioxidanactivityt PICs
Ventricular
dilation
Scar
formation
Cardiac
hypertrophy
MMPs
Autonomic
̄BrS dysfunction
̄LV function
Collagen
MI area content
Inhibition
EXERCISE
TRAINING
Fig. 9.2 Main effects of exercise training (ET) in experimental myocardial infarction (MI).
Aerobic ET performed on a rodent-adapted treadmill is the most studied method. BrS baroreflex
sensitivity, LV left ventricle, ROS reactive oxygen species, PICs proinflammatory citokynes,
MMPs matrix metalloproteinases
I.C. Moraes-Silva et al.