Effects Of Six Weeks Inspiratory Muscle Strength Training On Respiratory Muscle Electromyography

Abstract

Inspiratory muscle strength training (IMST) holds promise as a non-pharmacologic treatment that can improve respiratory muscle strength and reduce blood pressure in hypertensive adults. There is a gap in knowledge regarding the specific respiratory mechanisms that gives rise to these favorable outcomes. Here, I explore the effect of IMST on respiratory muscle fatigue, blood pressure, and heart rate in recreationally active men and women. Four subjects underwent a 6-week intervention comprising 30 breaths a day 5 days a week with a respiratory muscle fatigue protocol pre and post intervention. Pre-post intervention measures consisted of resting blood pressure, heart rate, and surface electromyographic (EMG) recordings of the scalene, parasternal, and oblique muscles. The effects of 6 weeks IMST on respiratory muscle fatigue were evaluated in the context of a fatigue protocol and by assessment of the centroid frequency of EMG power spectrum. My preliminary results in 4 subjects failed to show definitive results. I hypothesize that confounding factors, namely individualized breathing strategies contributed considerable variation to the patterns of respiratory muscle activation exhibited by our participants and invalidating pre-post comparisons of EMG power. Future studies should control for breathing patterns within subjects (i.e. across pre-post fatigue protocols) to ensure consistent patterns of respiratory muscle activation. Additionally, care should be taken to ensure uniformity of instructions across both fatigue protocols and daily IMST i.e., use of a diaphragmatic breathing pattern, to minimize between subject differences in respiratory muscle activation.