Respiratory muscle training: a mechanism study (706.22)

Abstract

Previous work has shown that hypertensive patients that undertake 8 weeks of inspiratory muscle strength training exhibit significant declines in systolic and diastolic blood pressure [Ferreira et al., 2011], and our lab has been able to reproduce these results in a healthy young adult population over a 6 week training period [unpublished data]. The mechanism underlying this change is not known. Here, we compare inspiratory muscle strength training (‐ pressure, + lung volume) against four other training protocols: deep breathing (+ lung volume), Mueller maneuver (‐ pressure), expiratory muscle strength training (+ volume, + pressure), and placebo, to determine which parameter may affect blood pressure. Fifty healthy adult volunteers (ages 18‐30) were randomly assigned to one of the five treatment groups and undertook 5 minutes of supervised training, 5 days a week, over a period of 6 weeks. After 4 weeks, preliminary findings from fifteen men and women show reductions in systolic and diastolic blood pressure for individuals in inspiratory (‐8.0/‐2.3) and expiratory (‐9.6/‐2.1) muscle strength training groups as well as the Mueller maneuver (‐4.4/‐3.4) group, compared to no change in the placebo group. On this basis we suggest that the large pressure swings associated with both respiratory resistance training and Mueller maneuvers may contribute to improvements in blood pressure. Our findings support additional studies aimed at assessing the effects of training on efferent mechanism(s), such as sympathetic outflow, that may underpin alterations in blood pressure.