The Effect of Eight Weeks of Inspiratory Muscle Strength Training on Central Blood Pressure and Aortic Stiffness Among Young Adults with Obesity

INTRODUCTION: Increased central blood pressure (BP) and aortic stiffness—indexed as carotid-to-femoral pulse wave velocity (cfPWV)—are independent risk factors for cardiovascular disease. Obesity is associated with increased central BP and cfPWV. Inspiratory muscle strength training (IMST) is an effective intervention for improving peripheral BP and vascular endothelial function. Eight weeks of IMST lowered peripheral and central BP but not cfPWV among young adults with elevated BP. However, previous work did not investigate the effect of IMST on central BP and cfPWV among young adults with obesity. PURPOSE: The purpose of this study is to test the hypothesis that 8 weeks of IMST would improve (lower) central BP and cfPWV, among young adults with obesity. METHODS: Using a double-masked, parallel-arm, sham-control design, we randomized otherwise healthy young adults (20–35 yrs) with obesity (body mass index BMI 30–40 kg/m 2 ) to 8 weeks of daily IMST training at 75% (IMST) or 15% (SHAM) of their maximal inspiratory pressure (MIP). Before and after training, we measured supine brachial BP, central BP, and cfPWV after 5 minutes of quiet rest. For normal data, we report data as mean ± SD and compare mean changes (Δ; post−pre) with unpaired t-tests and Cohen’s d effect sizes. For non-normal data, we report data as median IQR and compare mean changes with Mann-Whitney U tests and rank biserial effect sizes (rbc). RESULTS: Participants (n = 21) were: 26 ± 4 yrs; 57% Female; 76% White; 38% Latine/Hispanic. There were no baseline differences for BMI (IMST: 32.9 ± 2.7 vs. SHAM: 34.2 ± 2.6 kg/m 2 , P = 0.27, d = 0.50), age (IMST: 24 1 vs. SHAM: 27 6 yrs, P = 0.37, rbc = 0.24), MIP (IMST: 96 ± 26 vs. SHAM: 117 ± 38 cmH 2 O, P = 0.17, d = 0.62), brachial BP (systolic: IMST: 120 ± 9 vs. SHAM: 116 ± 10 mmHg, P = 0.35, d = 0.42; diastolic: IMST: 72 ± 8 vs. SHAM: 69 ± 5 mmHg, P = 0.49, d = 0.31), central BP (systolic: IMST: 108 ± 9 vs. SHAM: 105 ± 8 mmHg, P = 0.54, d = 0.27; diastolic IMST: 72 ± 9 vs. SHAM: 70 ± 5 mmHg, P = 0.46, d = 0.33), or cfPWV (IMST: 5.6 ± 1.0 vs. SHAM: 5.3 ± 1.0 m/s, P = 0.33, d = 0.44). Training compliance was not different between groups (IMST: 84 ± 14 vs. SHAM: 83 ± 11%, P = 0.78, d = 0.13). The ΔMIP was not different between groups (IMST: 32 ± 27 cmH 2 O vs. SHAM: 17 ± 29 cmH 2 O, P = 0.25, d = 0.52). The Δbrachial systolic BP was lower after IMST (IMST: -4 ± 6 vs. SHAM: 4 ± 6 mmHg, P = 0.02, d = 1.12), but not the Δbrachial diastolic BP (IMST: -1 ± 4 vs. SHAM: 2 ± 3 mmHg, P = 0.06, d = 0.89). The Δcentral systolic BP (IMST: -2 ± 6 vs. SHAM: 4 ± 5 mmHg, P = 0.046, d = 0.93) and the Δcentral diastolic BP (IMST: -1 ± 4 vs. SHAM: 2 ± 4 mmHg, P = 0.04, d = 0.95) were lower after IMST. The ΔcfPWV was lower after IMST (IMST: -0.2 ± 0.5 vs. SHAM: 0.3 ± 0.6 m/s, P = 0.04, d = 0.99). CONCLUSIONS: Although MIP increased in both groups, there was not a significant difference in the ΔMIP between IMST and SHAM. However, these preliminary findings support previous work, which found that high-intensity inspiratory muscle strength training lowered brachial and central systolic BP among young adults. These new findings suggest that this training may improve brachial BP, central BP, and aortic stiffness among young adults with obesity. More work is needed to confirm these preliminary findings. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.