Mechanisms of exercise‐induced improvements in the contractile apparatus of the mammalian myocardium

Abstract

One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and we argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function.

Angiotensin-(1–7) attenuates hypertension in exercise-trained renal hypertensive rats

“…In agreement with these findings, the LV function was not altered in 2K1C rats in this study. However, swimming training improved cardiac systolic function in 2K1C rats, which could be because of the normalization or increase of the contractile protein enzymatic activity and of myosin isoenzyme (29,48). In the present study, ANG-(1-7) infusion did not show any effect on LV functions.…”

Physical Activity in the Prevention and Treatment of Coronary Artery Disease

“…Exercise training was shown to induce reverse cardiac remodeling in patients with heart failure with reduced left ventricular ejection fraction 75, 77. The impact of exercise training on intracellular calcium handling and myocardial contractility was extensively studied by Kemi and Wisloff and has been reviewed elsewhere 78. Nonetheless, a significant increase in cardiac output as a result of eccentric myocardial hypertrophy and increased myocardial contractility, which is seen in healthy athletes, could not be detected in patients with CAD in the absence of heart failure 2, 69, 76, 79.…”

Exercise and creatine supplementation attenuate recovery from myocardial ischaemia

“…In the previous studies, various positive effects of exercise have been documented. Exercise is thought to improve function of the heart (Kemi & Wisloff 2010, Hansen et al 2012, Kwan & Balady 2012) and vessels (Whyte & Laughlin 2010). Moreover, insulin sensitivity increases by sports (Matos et al 2010, Helge et al 2011, Maarbjerg et al 2011, Ismail-Beigi 2012, and even the differentiation to adipocytes seems to be halted by exercise (Sakurai et al 2010).…”