Diaphragmatic Breathing Techniques: What the Peer-Reviewed Evidence Shows
Diaphragmatic breathing, sometimes called belly or abdominal breathing, uses the diaphragm, the main breathing muscle between your chest and abdomen, to draw air deeper into the lungs. On the inhale, your belly gently expands while your chest stays mostly still. This differs from the shallow upper-chest breathing many of us slip into during daily stress. The practice shows up in traditional approaches like qigong, and researchers have examined it in clinical settings through randomized trials and systematic reviews.
Here is what stands out from the published studies.
One solid review comes from Hopper and colleagues in 2019. They examined diaphragmatic breathing for stress reduction in adults and found it lowered respiratory rate, salivary cortisol, blood pressure, and self-reported stress scores. The studies included were small and varied in length, but the pattern held across both physiological and psychological measures. This gives a clear sense that the technique can help dial down the body’s stress response in noticeable ways.
Ma and co-authors ran a 2017 randomized controlled trial with healthy adults. Those who practiced diaphragmatic breathing showed better sustained attention, less negative mood, and lower cortisol compared with the control group. The results point to real mental and physical shifts from regular sessions. It is one of the cleaner trials in this area, with direct measurements that help explain why so many people feel clearer and calmer after consistent practice.
For people dealing with lung conditions, Hamasaki’s 2020 narrative review brought together earlier systematic reviews and fifteen RCTs. Diaphragmatic breathing helped improve exercise capacity, breathing efficiency, and quality of life in COPD patients. Evidence for asthma looked promising but needs more work. The review highlights how this simple shift in breathing pattern can make everyday activities feel less taxing for those with chronic respiratory issues.
On the digestive side, Halland’s 2021 randomized trial focused on upright GERD. Patients using diaphragmatic breathing after meals had fewer reflux episodes. The technique appeared to strengthen the pressure difference between the stomach and esophagus, offering a clear mechanism for symptom relief. For anyone who experiences post-meal discomfort, this kind of targeted use stands out as particularly practical.
Newer work, including Kwon’s 2025 systematic review of dozens of RCTs, echoes these findings. It notes that benefits depend on the condition and that we still need larger, more consistent trials. The review covers a range of applications and reinforces that diaphragmatic breathing is not a cure-all, but it shows reliable effects in several key areas.
Other research hints at short-term gains for pain, anxiety, post-stroke recovery, and mobility. Many of these trials remain modest in size and duration, which is common in this field. Still, the overall body of evidence builds a compelling case for giving the practice a fair try.
How to Practice It
The studies often used straightforward protocols you can follow at home. Begin in a quiet spot. Lying on your back with knees bent works well at first, especially if you are new to it or want to build awareness.
Put one hand on your chest and the other on your belly. Breathe in slowly through your nose for four to six seconds so your belly rises while your chest barely moves. Let the exhale last a bit longer, six to eight seconds, through nose or mouth. Aim for five to ten minutes, building up as it feels natural. Many studies used sessions in this range, sometimes repeated daily.
For stress or focus, many protocols use paced rhythms similar to the Ma study. After meals, the upright version from the GERD trial can help settle digestion. Once lying down feels easy, shift to sitting or standing and weave it into daily routines or movement practices. You might try it during a quiet moment at your desk, while walking, or as part of a longer qigong session.
Consistency mattered more than perfection in the research. Start gently, stay aware of your body, and check with a clinician if you have respiratory or other health conditions. The beauty of this approach is that it requires no equipment and fits into almost any schedule.
This kind of breathing offers a simple, no-cost way to support your nervous system, lungs, and digestion. It connects older traditions with measurable effects in modern trials, which makes it practical for everyday use. Experiment with it over a couple of weeks and notice what shifts for you. Small changes in how you breathe can add up in surprising ways.
Like what you read? Keep exploring…
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References
Halland, M., Bharucha, A. E., Crowell, M. D., Ravi, K., & Katzka, D. A. (2021). Effects of diaphragmatic breathing on the pathophysiology and treatment of upright gastroesophageal reflux: A randomized controlled trial. American Journal of Gastroenterology, 116(1), 86–94.
Hamasaki, H. (2020). Effects of diaphragmatic breathing on health: A narrative review. Medicines, 7(10), Article 65.
Hopper, S. I., Murray, S. L., Ferrara, L. R., & Singleton, J. K. (2019). Effectiveness of diaphragmatic breathing for reducing physiological and psychological stress in adults: A quantitative systematic review. JBI Database of Systematic Reviews and Implementation Reports, 17(9), 1855–1876.
Kwon, C.-Y., Won, J., & Lee, B. (2025). The health effects of diaphragmatic breathing: A systematic review. Complementary Therapies in Medicine, 96, Article 103317.
Ma, X., Yue, Z.-Q., Gong, Z.-Q., Zhang, H., Duan, N.-Y., Shi, Y.-T., Wei, G.-X., & Li, Y.-F. (2017). The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Frontiers in Psychology, 8, Article 874.