IJCS | Volume 32, Nº4, July/August 2019

411 Bavaresco Gambassi et al. Exercise and cardiovascular variables poststroke Int J Cardiovasc Sci. 2019;32(4):408-413 Review Article According to Harris and Eng, 17 Mehta et al., 18 and Wist et al., 19 it is possible to improve functional components of poststroke individuals through the practice of resistance training. Additionally, Francica et al., 21 have shown that aerobic exercise can benefit functional and cardiovascular abilities in poststroke individuals. Pang et al., 22 have also observed improvement in cardiorespiratory capacity of poststroke individuals who underwent aerobic exercise training. In line with some of the above findings, seven randomized controlled trials showed benefits on aerobic fitness provided by systematized exercise programs. 36-42 However, in the last 10 years, we found only two studies addressing ACC and exercise in stroke survivors. 42-44 Thus, once again, we emphasize the need for further randomized studies to investigate the effects of exercise training on negative changes in ACC caused by stroke. ACC is performed by the influence of the sympathetic and parasympathetic branches on the myocardial cells promoting either increase or decrease of the heart rate, according to the needs of the organism. Such variation in heart rate moment by moment in response to the body’s need is called heart rate variability. When heart rate variability is normal, it indicates the ability of ACC to respond to multiple physiological stimuli, such as exercise training, mental stress, respiration, and metabolic alterations. 45-47 Any negative change in the interaction between central and peripheral nervous systems (afferent and/or efferent pathways) reduces heart rate variability by compromising ACC with consequent health impairment. 9-11 According to a study by Kleiger et al., 48 there is a strong relationship between mortality risk and heart rate variability in individuals after acute myocardial infarction. A high heart rate variability represents good functioning of the autonomic nervous system, positively impacting the health status of an individual, whereas the reduction of this variable indicates losses on the ACC and higher risk of cardiac death. 12,13 According to a study conducted by Francica et al., 49 poststroke individuals had lower heart rate variability when compared to controls. Although few studies have attempted to investigate the effects of exercise on ACC poststroke, it has been demonstrated that non-pharmacological strategies (exercise training) may increase heart rate variability in other populations and consequently reduce the risk for cardiovascular death. 50-57 Conclusions This review found that in the last ten years, few randomized clinical trials involving aerobic training, resistance training, and cardiovascular and autonomic variables after chronic stroke have been performed. Evidence from some studies suggests that exercise training seems effective in improving cardiovascular and autonomic variables in stroke survivors. More randomized controlled trials are needed to assess the role of exercise training in the management of stroke survivors, so that health professionals canmake informed choices when prescribing exercise training to improve the impaired variables above mentioned. Acknowledgments Bruno Bavaresco Gambassi is grateful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). Bruno Rodrigues received financial support from CNPq-BPQ. Author contributions Conception and design of the research: Gambassi BB, Santos CP, Queiroz C, Schwingel PA, Almeida FJF, Almeida AERAF, Ribeiro JR, Novais TMG, Rodrigues B. Acquisition of data: Gambassi BB, Santos CP, Queiroz C, Schwingel PA, Almeida FJF, Almeida AERAF, Ribeiro JR, Novais TMG, Rodrigues B. Analysis and interpretation of the data: Gambassi BB, Santos CP, Queiroz C, Schwingel PA, Almeida FJF, Almeida AERAF, Ribeiro JR, Novais TMG, Rodrigues B. Writing of the manuscript: Gambassi BB, Santos CP, Queiroz C. Critical revision of the manuscript for intellectual content: Gambassi BB, Schwingel PA, Almeida FJF, Rodrigues B. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding This study was funded by CNPq. Study Association This study is not associated with any thesis or dissertation work.