Does high-resistance inspiratory muscle strength training (IMST) improve blood pressure, endothelial function, and arterial stiffness in midlife/older adults with elevated systolic blood pressure?
Inspiratory Muscle Strength Trainer, a randomized trial in 18 participants (J Am Heart Assoc 2021, PMID 34184544) — high-resistance IMST significantly decreased casual systolic blood pressure from 135±2 mm Hg to 126±3 mm Hg, with approximately 75% of this reduction sustained 6 weeks post-training. Sham training had no effect on blood pressure or endothelial function, and neither IMST nor sham training influenced arterial stiffness.
Source: J Am Heart Assoc 2021, PMID 34184544 ↗ · Research map · How Magellan grades evidence · evidence confidence: high
J Am Heart Assoc · 2021 · PMID 34184544 · DOI 10.1161/JAHA.121.020980
Six weeks of high-resistance inspiratory muscle training can lower blood pressure and improve blood vessel function in older adults.
The question
Does high-resistance inspiratory muscle strength training (IMST) improve blood pressure, endothelial function, and arterial stiffness in midlife/older adults with elevated systolic blood pressure?
What they tested
The study hypothesized that 6 weeks of high-resistance IMST would improve blood pressure, endothelial function, and arterial stiffness, and also investigated potential mechanisms and long-lasting effects.
How they did it
A double-blind, randomized, sham-controlled trial was conducted with 36 midlife/older adults (aged 50-79 years) who had systolic blood pressure ≥120 mm Hg. Participants were randomized to either high-resistance IMST (75% maximal inspiratory pressure, n=18) or low-resistance sham training (15% maximal inspiratory pressure, n=18) for 30 breaths/day, 6 days/week for 6 weeks. Blood pressure, endothelial function (brachial artery flow-mediated dilation), and arterial stiffness were measured, along with markers of NO bioavailability, eNOS activation, reactive oxygen species, C-reactive protein, and circulating metabolites.
What they found
High-resistance IMST significantly decreased casual systolic blood pressure from 135±2 mm Hg to 126±3 mm Hg, with approximately 75% of this reduction sustained 6 weeks post-training. Casual diastolic blood pressure also modestly decreased from 79±2 mm Hg to 77±2 mm Hg. Twenty-four hour systolic blood pressure was lower after IMST compared to sham training. Brachial artery flow-mediated dilation improved by approximately 45% with IMST. Serum from participants after IMST showed increased NO bioavailability, greater endothelial NO synthase activation, and lower reactive oxygen species bioactivity in cultured human umbilical vein endothelial cells. IMST also decreased C-reactive protein and altered select circulating metabolites. Sham training had no effect on blood pressure or endothelial function, and neither IMST nor sham training influenced arterial stiffness.
| Before IMST | 135 | |
|---|---|---|
| After IMST | 126 |
Casual systolic blood pressure decreased from 135 mm Hg to 126 mm Hg after 6 weeks of high-resistance IMST.
What it means
High-resistance IMST is a safe and highly adherable lifestyle intervention that effectively improves blood pressure and endothelial function in midlife/older adults with above-normal initial systolic blood pressure.
Limitations
The abstract does not explicitly state any limitations of the study.
Where the published abstract does not list limitations, we say so rather than inventing them. Read the full paper on PubMed before drawing conclusions.
The paper at a glance
| Magellan’s evidence label | high-resistance breath loading (our label for this citation — see PubMed for the paper’s own title and authors) |
|---|---|
| Journal | J Am Heart Assoc |
| Year | 2021 |
| PMID | 34184544 ↗ |
| DOI | 10.1161/JAHA.121.020980 ↗ |
| Topic | Cardiovascular & vascular aging |
Read the source: PubMed record (authors, abstract, full citation) ↗ · Publisher via doi.org ↗
Where Magellan uses this paper
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Inspiratory Muscle Strength Trainer
In randomized trials, most prominently sham-controlled work from the University of Colorado in midlife and older adults, about six weeks of high-resistance IMST performed a few minutes a day lowered systolic blood pressure by roughly 9 mmHg and improved vascular endothelial function, with much of the effect…
An inspiratory muscle strength trainer is a small handheld device that imposes a high resistance on…
Research describes the compound or intervention studied. It is not a claim about any specific product.
Molecules & mechanisms in this paper
Each of these is named in the paper’s own words above. Open the monograph for the full mechanism and its other citations.
Cite this page
These citations point at this summary. To cite the original paper with its full author list, use the PubMed record or doi.org.
Magellan Longevity. (2026). Does high-resistance inspiratory muscle strength training (IMST) improve blood pressure, endothelial function, and arterial stiffness in midlife/older adults with elevated systolic blood pressure? [Plain-English summary of J Am Heart Assoc 2021, PMID 34184544, DOI 10.1161/JAHA.121.020980]. Magellan Longevity. https://magellanlongevity.com/study/s165.html@misc{magellan_s165,
title = {Does high-resistance inspiratory muscle strength training (IMST) improve blood pressure, endothelial function, and arterial stiffness in midlife/older adults with elevated systolic blood pressure?},
author = {{Magellan Longevity}},
year = {2026},
howpublished = {\url{https://magellanlongevity.com/study/s165.html}},
note = {Plain-English summary of PubMed PMID 34184544; DOI 10.1161/JAHA.121.020980; J Am Heart Assoc 2021. Reviewed by Gabriel Radu, DO},
urldate = {2026-08-11}
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