Effectiveness Of Inspiratory Muscle Strength Vs. Aerobic Exercise On Blood Pressure And Vascular Function In Patients With Hypertension

PURPOSE: Moderate intensity aerobic exercise (AE) training is recommended for lowering blood pressure and improving vascular function in hypertensive patients. However, adherence rates are low due to busy lifestyles. Recently, high-resistance inspiratory muscle strength training (IMST) has emerged as a more accessible and time-efficient alternative. The purpose of this study was to evaluate and compare the effectiveness of IMST versus AE on blood pressure and vascular function in hypertensive patients. METHODS: We enrolled 25 hypertensive patients (59 ± 4 years; 9 males, 19 females) who were randomly assigned to the AE group (n = 12) and the IMST group (n = 13). IMST was performed at 75% of maximal inspiratory pressure (PImax) for 30 breaths/day, taking about 8 minutes, 5 days/week, and AE at 70% of heart rate reserve for 30 minutes/day, 5 days/week, for 8 weeks, followed by a 4-week detraining period. We measured brachial and central systolic blood pressure (SBP), brachial artery endothelial function, carotid artery compliance, and peak oxygen uptake at baseline, post-intervention, and post-detraining. RESULTS: Brachial SBP significantly decreased in both IMST group (from 124 ± 19 mmHg to 116 ± 13 mmHg, p < .05) and AE groups (130 ± 13 mmHg to 123 ± 10 mmHg, p < .05), with no significant difference between them. Post-detraining, the AE group showed a sustained reduction in SBP (123 ± 10 mmHg, p < .05) compared to baseline, while the IMST group's SBP tended to return to baseline levels (119 ± 15 mmHg, p = .06). Central SBP decreased in both groups, with sustained reductions only in AE (119 ± 9 mmHg, p < .05). Endothelial function improved only in the IMST group (3.21 ± 1.6% to 4.70 ± 1.7%, p < .05), with no significant change in the AE group (2.95 ± 1.6% to 3.95 ± 1.3%, p > .05). Both interventions significantly improved carotid artery compliance, which persisted post-intervention (both, p < .05). However, there were no significant changes in peak oxygen uptake. CONCLUSIONS: IMST and AE similarly reduce SBP and arterial compliance without affecting peak oxygen uptake. Notably, IMST more effectively improves endothelial function than AE, presenting it as a viable, time-efficient antihypertensive strategy for individuals with hypertension.