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In addition, careful attention to selection of anesthesia and excision beforeperforming the experiment are essential to the collection of data [ 3 ]. Using anes-
thetic or any drug before can influence several factors in working heart model of
rats [ 32 , 33 ]. Various researches are designed to evaluate the beneficial or detri-
mental effect of exercise in animals exhibiting specific cardiovascular diseases,
such as cardiac hypertrophy, hypertension, ischemic heart disease, and heart fail-
ure [ 1 , 2 , 10 , 15 , 17 , 20 , 24 , 34 , 35 ]. As cardiovascular disease models would most
likely pose limitations to exercise capabilities or even aggravate an animal’s clini-
cal condition, researchers must consider various factors to select the best animal
model for their researches. Many of these alternatives are genetically modified
models which may offer better choices of achieving experimental goals [ 31 , 34 ].
However, human and animal hearts are different, depending on the specific animal
model used. The advantages and disadvantages of using animal models in study-
ing cardiac contraction deeply underlined [ 3 , 6 ]. With all animal-based research,
a team-based approach to developing performance-based design and implementa-
tion standards are needed in order to attain favorable results [ 3 ].
Overall, there is no golden standard for which animal model can be used for allcardiovascular researches. Depending on the research goals, animal model needs to
be chosen carefully and whether outcomes will be affected and whether these can
eventually be adapted for human use [ 6 ].
3 Animal Used in Acute and Chronic Cardiac Exercises
3.1 Modalities
As previously mentioned, efficiency and endurance capacity of the heart become
more efficient with aerobic exercise and interestingly muscle strength and endurance
increase with resistance exercise [ 11 , 28 ]. The muscle activity performed during
exercise has both mechanical and metabolic properties which can differ significantly
[ 28 ]. Review of previous literatures have shown that aerobic exercise models are
most suitable in studying cardiovascular functions [ 1 , 3 , 20 , 22 ]. Acute exercise is
defined as a single bout of physical activity or exercise, and regular bouts of acute
exercise eventually lead to what is termed as chronic exercise. Accordingly, experi-
mental aerobic exercise models in animals use either voluntary or forced activity.
Effects of both acute exercise and chronic exercise have been well characterized and
reviewed in physiological conditions, and was found to affects human cardiovascular
disorders or diseases and animal disease models [ 36 ]. A wide range of cardiovascu-
lar changes after an exercise from studies in animal models is linked with behavioral
effects in human [ 6 , 8 , 11 , 36 ]. Normally, physiological changes are described as an
acute or chronic activation of the stress response [ 37 , 38 ]. These stress responses are
normal and adaptive facets of body in order to maintain or restore homeostasis to
acute exercise. Somehow, the common problem of exercise studies is that chronic or
V.T. Thu et al.