Alterations in ventricular mass and performance induced by exercise training in man evaluated by echocardiography.

Abstract

Few data are available regarding the effects of exercise training upon cardiac structure and performance in man. We evaluated the echograms of 24 normals before (PRE) and after (POST) 11 weeks of endurance exercise training. Conditioning consisted of a walk-jog-run protocol at 70% maximal heart rate for one hour four days per week. Training reduced heart rate and increased maximal duration and estimated oxygen consumption of treadmill exercise. Compared to PRE, the echogram in the POST training period revealed an increased left ventricular (LV) end-diastolic dimension (EdD), a decreased end-systolic dimension (EsD) and thus an increased stroke volume (EdD3-EsD3) and shortening fraction (EdD-EsD)/EdD). Cardiac output (CO) and peripheral vascular resistance (BP/CO X 80) were identical PRE and POST conditioning. Importantly, an increase in mean fiber shortening velocity was observed POST training as were increases in LV wall thickness, ECG voltage of S in V1 + R in V5, and LV mass. Thus endurance training was accompanied by increases in both LV dimension and mass as well as LV shortening fraction and contraction velocity as observed by echocardiogram.

Decanoato de nandrolona aumenta a parede ventricular esquerda, mas atenua o aumento da cavidade provocado pelo treinamento de natação em ratos

“…Increase in the ventricular cavity, without corresponding increase in the wall thickness, verified in the trained and untreated animals, suggests a cardioprotector effect caused by training. Hypertrophy of the left ventricle, caused by physical training, is associated with increase of the cavity size (5) . The steroid increased the wall thickness in the treated animals, both sedentary and trained.…”

“…Chronic treatment with high doses of AAS causes reduction in the antioxidant enzymes activity induced by exercise, and, consequently, reduces the cardioprotective mechanisms during an ischemia (4) . Endurance training caused physiological hypertrophy of the left ventricle in the cardiovascular system of humans, which was associated with increase of the cavity diameter (5) , while resistance training produced concentric hypertrophy (6) . AAS reduced complacence of the left ventricle with no alteration in the cardiac contrality of rats (7) , and their simultaneous administration with training increased collagen concentration on the wall of the right ventricle in dogs (8) .…”

“…However, increase in systolic blood pressure (SBP) and diastolic blood pressure (DBP) was verified in individuals submitted to high AAS doses (11,12) . There is massive controversy concerning the physical training benefits when associated with the use of anabolic steroids, as well as when the AAS are independently used, especially when referring to their effects on the heart and its dimensions (3,5) . The physiological alterations provided by physical training may be more or less evident, depending on its kind, duration, frequency, exercise intensity and also on the individual characteristics (9,13) .…”

Reversal of adaptive left ventricular atrophy following electrically-stimulated exercise training in human tetraplegics

“…Study subjects underwent one month of quadriceps muscle trammg using transcutaneous electrical current (compensated monophasic rectangular wave, 40 Hz, 375 microseconds pulse duration, constant current, Therapeutic Tech nologies, Inc.) applied to the anterior thigh using three carbon silastic electrodes.…”

Heat acclimation and exercise training interact when combined in an overriding and trade-off manner: physiologic-genomic linkage

“…In contrast to AC, endurance EX increases cardiac muscle mass (hypertrophy) and oxygen consumption (6,36). Fast myosin with high ATPase activity (V1) predominance and increased contractility is induced by changes in the regional contractile properties of the heart (7).…”