Effects of inspiratory muscle training on autonomic control: systematic review

ABSTRACT The autonomic nervous system dysfunction has an important role on the physiopathology of some diseases. A possible option to improve the autonomic control is the inspiratory muscle training (IMT). The aim of this study was to systematically review the available literature about the effects of this training modality on autonomic control. A search was performed for controlled and randomized clinical trials on database MEDLINE, PEDro, SciELO and LILACS by two independent reviewers, who also evaluated the methodologic quality (PEDro scale). 181 articles were found and, after elegibility criteria analysis, four studies were included. The included studies showed good methodological quality and assessed the effect of IMT on the autonomic control of participants with risk factors for cardiovascular disease. The autonomic control was evaluated by heart rate variability (HRV) analysis and by noradrenaline plasma levels. The IMT improved autonomic control in 3 studies, reducing the sympathetic nervous system (noradrenaline plasma levels; LF nu - HRV) and increasing the vagal nervous system (HF un - HRV). It is concluded that IMT may be a therapeutic alternative to improve the autonomic control.