Resistance training and modulation of cardiac autonomic control in animal models: a systematic review

Abstract

The purpose of the present review is to systematically evaluate the existing literature on the effects of resistance training (RT) on cardiac autonomic control in animal models. Electronic search was conducted in Pubmed, PEDro and Scopus databases from inception till June 2018. Randomised controlled trials and quasi-experimental trials which investigated the effects of RT (for at least 4 weeks) on cardiac autonomic control (assessed either by heart rate variability, baroreflex sensitivity or post-exercise heart rate recovery) in animal models were included. Out of the total 3,442 studies retrieved by the electronic search, 9 were found to be suitable as per the eligibility criteria and were included in this review. The majority of these studies (6 out of 9) demonstrated improvement in cardiovascular autonomic control after RT in animals; however, three studies did not illustrate any significant change. Standardised mean differences (SMD) showed a significant effect of RT on root mean square of successive differences between adjacent inter-beat (R-R) intervals (RMSSD) [SMD (confidence interval (CI)) = 4.56 (2.89, 6.23); P<0.0001] and bradycardic response to change in arterial blood pressure [SMD (CI)=-2.27 (-4.50, -0.03; P=0.05)] whereas no significant change was observed for other variables of cardiac autonomic control post-RT. The present systematic review do not give a clear conclusion regarding the effect of RT on cardiac autonomic control in animal models and thus highlight the need for good quality research in future.