The effectiveness of functional inspiratory muscle training on exercise capacity and peripheral muscle strength in patients with essential hypertension: a three-arm randomized controlled trial.

Abstract

Background: The effect of inspiratory muscle training (IMT) applied along with function in Hypertension (HT) patients is uncertain. In this study, it was to determine the effectiveness of functional IMT (F-IMT) on functional lower and upper exercise capacity, mobility, peripheral and respiratory muscle strength, blood pressure, fatigue, physical activity, and quality of life (HRQoL) in HT patients.

Methods: Prospective, randomized controlled, assessor-blinded, parallel three-armed trial. Forty-five patients with HT were divided into F-IMT group (IMT with 50% maximal inspiratory pressure (MIP)/4 weeks + exercise and IMT with 50% MIP/4 weeks, n = 15), IMT group (MIP 50%, n = 15) and control group (CG, breathing exercises, n = 15). 6-min walking test (6-MWT), 6-min pegboard ring test (6PBRT), 1-min sit to stand test (1STS), mobility, peripheral muscle strength, MIP, maximal expiratory pressure (MEP), systolic& diastolic blood pressure (SBP, DBP), fatigue, physical activity, and HRQoL were evaluated before and after 8 weeks of training.

Results: Increases in 6-MWT were higher in F-IMT (p < 0.001). 6PBRT, 1STS, quadriceps femoris strength were improved and SBP reduced in F-IMT and IMT than CG (p < 0.001). Mobility, handgrip, HRQoL, and physical activity level increased within groups (p < 0.05). MIP increased within F-IMT and IMT; MEP, fatigue, DBP improved only within F-IMT (p < 0.05).

Conclusions: F-IMT is more effective in enhancing exercise capacity, reducing fatigue and DBP, and improving MEP. Both IMT and F-IMT show similar benefits for upper extremity exercise capacity, quadriceps femoris strength, SBP, and MIP. Mobility, HRQoL, and physical activity levels are increased with F-IMT, IMT, and breathing exercises.

Trial registration: ClinicalTrials.gov Identifier: NCT06343246 (03/29/2024).