We have shown that none of the pathological cardiac hypertrophy
molecular markers, atrial natriuretic factor (ANF) or
α-myosin heavy chain (α-MHC)-to-β-MHC ratio, were changed
in resistance-trained rats (17). It is well known that cardiomyocyte
contractility depends on the expression of α- and β-MHC,
since MHC is the major contractile protein of the heart, and is
crucial to the efficiency of cardiac performance. The α/β-MHC
ratio varies in response to physiological and pathological
signaling. Studies have shown a shift from α- toward β-MHC
composition of the adult heart under pathological conditions accompanied
by higher expression of fetal gene reprogramming,
which correlates with impaired cardiac performance (18). Thus,
resistance training induces physiological concentric cardiac
hypertrophy, and could be used as a good exercise modality to
compare physiological and pathological concentric hy