Cardiovascular adaptive responses in rats submitted to moderate resistance training

Abstract

The present study investigated the effects of 8 week of resistance training (RT) on hemodynamic and ventricular function on cardiac myosin ATPase activity, and on contractility of papillary muscles of rats. Groups: control (CO), electrically stimulated (ES), trained at 60% (TR 60%) and 75% of one repetition maximum (1RM) (TR 75%). Exercise protocol: 5 sets of 12 repetitions at 60 and 75% of 1RM, 5 times per week. The CO and ES groups had similar values for parameters analyzed (P > 0.05). Blood pressure (BP), heart rate (13%), left ventricle systolic pressure (LVSP 13%) decreased and cardiac myosin ATPase activity increased in the TR 75% group (90%, P < 0.05). The contractile performance of papillary muscles increased in trained rats (P < 0.05). Eight weeks of RT was associated with lowering of resting BP, heart rate and LVSP, improvements in contractility of the papillary muscle and an increase of cardiac myosin ATPase activity in rats.

Eccentric and concentric cardiac hypertrophy induced by exercise training: microRNAs and molecular determinants

“…The improvement in cardiomyocyte contractility was due to an increase in myosin ATPase activity and an enhanced Ca 2+ -influx (16). The double Figure 1.…”

Resistance Exercise Restores Endothelial Function and Reduces Blood Pressure in Type 1 Diabetic Rats

“…In this study, resistance exercise was performed in a squat device for rats, and proved to be effective in mimicking the beneficial cardiovascular effects found in humans practicing that type of exercise 19,20 . Tail electrical stimulation was required for the animals to perform the squat movement.…”

“…Training loads were readjusted every two weeks by using a new 1RM test 18 . The parameters of electrical stimulation were those described by Cássia Cypriano Ervati Pinter et al 19 . Electrical stimulation (20 V, 0.3-second duration, 3-second interval) 20 with electrodes (Valu Trode, Model CF3200, Axelgaard, Fallbrook, CA, USA) fixed to the animals' tails and connected to an electrical stimulator (BIOSET, Physiotonus Four, Model 3050, Rio Claro, SP, Brazil) was used to make the animals performed their exercise sets.…”

Effect Of Resistance Training On Myocardial Contractility In Vitro After Sleep Deprivation

“…In contrast, resistance training at pre-determined loads (60-70% of 1RM) has been shown to improve myosin ATPase activity and papillary muscle contractility. 8 Regarding aerobic training, previous studies have shown higher DT in trained animals than in controls. 16,25 Analysis of contractile response of papillary muscles to stretching allowed the assessment of the Frank-Starling relationship.…”

“…In addition to reducing resting arterial pressure, left ventricular systolic pressure and heart rate, 8,9 resistance training can also increase papillary muscle isometric strength and its contractile performance. 10 Also, due to its effect on endocrine axes, resistance training can mitigate the catabolic effect of sleep deprivation.…”