Comparison of inspiratory muscle strength and aerobic exercise training and detraining on blood pressure in hypertensive patients

Background: This study evaluated the effectiveness of inspiratory muscle strength training (IMST) as a time-efficient alternative to widely recommended aerobic exercise (AE) for reducing and maintaining blood pressure in hypertensive patients. Methods: Twenty-eight hypertensive patients (aged 61 ± 7 years) were randomly assigned to IMST (n = 14) and AE (n = 14) groups. The IMST performed 30 breaths/session at 75% of maximal inspiratory pressure (PI_max), totaling about 8 minutes, 5 days/week. The AE group exercised at 70% of heart rate reserve for 30 minutes/session, 5 days/week. Both supervised interventions lasted 8 weeks, followed by a 4-week detraining period. Brachial and central systolic blood pressure (SBP) were taken at baseline, 8-week post-intervention, and post-detraining. Results: The mean (standard deviation) change in brachial SBP from baseline to 8 week post-intervention significantly decreased in both the IMST group [−9.1 (12.1) mmHg, P = 0.01] and the AE group [−6.2 (7.2) mmHg, P = 0.01], with no significant difference between groups (P = 0.46). Central SBP also significantly reduced in the IMST group [−9.0 (11.9) mmHg, P = 0.01] and in the AE group [−5.7 (6.2) mmHg, P = 0.01], with no significant difference between groups (P = 0.37). However, the IMST group did not show significant persistence in SBP reduction, whereas the AE group did. Conclusions: Both IMST and AE effectively reduced brachial and central BP after 8-week interventions in hypertensive patients. While IMST presents a time-efficient adjunctive option to AE, its long-term effectiveness remains uncertain.