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Diaphragm PacingNCT07620249

Effects of Combined Thoracic and Diaphragmatic Breathing on Cognitive and Psycho-Physiological Functions

A study testing thoracic expansion exercises and slow diaphragmatic breathing in people with Diaphragm Pacing, run by National Taiwan University Clinical Trial Center.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This study aims to investigate the effects of a combined thoracic expansion exercise (TEE) and slow diaphragmatic breathing (SDB) program on cognitive function, brain activation, psychological status, and head-shoulder posture in healthy young adults. Read more about this study

Who is it for?
Ages 18 to 30 yearsHealthy volunteers can take part
Conditions the study is for
Diaphragm Pacing
What is being tested?
thoracic expansion exercises and slow diaphragmatic breathing
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
60 participants
Where
No sites listed yet
Study dates
25 May 2026to 1 Feb 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 30 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • age between 18 to 30 years with at least a high school education to ensure baseline cognitive task comprehension
  • the ability to adhere to verbal instructions
  • no regular participation in formal breathing exercise or mindfulness training within the past six months.

Who cannot join

  • a history of musculoskeletal, cardiovascular, or cerebrovascular diseases which may interfere this study
  • history of respiratory disease or recent respiratory infection
  • diabetes mellitus with neuropathy, peripheral neuropathy, or other neurological disorders
  • major surgery within the past six months
  • Current or past major psychiatric disorders or cognitive impairment
  • use of medications significantly affecting cerebral hemodynamics or autonomic function (e.g., beta-blockers, vasodilators) within the past 2 weeks
  • use of psychotropic medications or substances known to alter cerebral blood flow, neural activation, or autonomic regulation (e.g., antidepressants, antipsychotics, anxiolytics, stimulants, or sedative-hypnotics).

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

About this study

Official title: The Effects of Combined Thoracic Expansion Exercises and Slow Diaphragmatic Breathing on Cognitive Function, Brain Activation, Psychological Status, and Head-Shoulder Posture in Healthy Adults

This study aims to investigate the effects of a combined thoracic expansion exercise (TEE) and slow diaphragmatic breathing (SDB) program on cognitive function, brain activation, psychological status, and head-shoulder posture in healthy young adults.

Being tested
thoracic expansion exercises and slow diaphragmatic breathing, Sham Block
Keywords
breathing exercise, autonomic regulation, cognitive function, functional near-infrared spectroscopy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • thoracic expansion exercises and slow diaphragmatic breathingOther

    4-week supervised training program, consisting of three 30-minute sessions per week. Thoracic expansion exercises consists of chest wall stretching and mobility drills. Followed by 15 minutes of progressive slow diaphragmatic breathing (4-s inhalation/6-s exhalation).

  • Sham BlockOther

    During sham TEE, participants perform comfortable thoracic movements without foam rollers or specific breathing coordination. During sham SDB, they maintain a spontaneous, natural respiratory rhythm in relaxed postures. Crucially, the sham protocol lacks the rhythmic pacing (4:6s), diaphragmatic depth cues, and resistance-based progression required to trigger the neuro-cognitive "respiratory-brain" axis.

Study groups in NCT07620249
Study groupRoleWhat they receive
rhythmic breathing exercise groupExperimentalThe rhythmic breathing exercise group will perform 10 minutes of thoracic expansion exercises followed by 15 minutes of progressive diaphragmatic breathing (4-s inhalation/6-s exhalation) to facilitate parasympathetic dominance.
Receives: Other: thoracic expansion exercises and slow diaphragmatic breathing
natural breathing exercise groupSham comparatorThe natural breathing exercise group performed sham thoracic expansion exercises and sham slow diaphragmatic breathing
Receives: Other: Sham Block

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change from baseline in Working Memory

    Assessed by the 2-back task. The outcome is calculated as the change in accuracy (percentage of correct responses) and reaction time. Accuracy range from 0% to 100%. Higher accuracy and lower reaction time indicate better working memory capacity.

    Measured: Baseline, Week 5 (post-intervention)

  2. Change from baseline in Inhibitory Control

    Measured by the Stop-signal task (SST). The outcome is the change in Stop-Signal Reaction Time (SSRT) in milliseconds. SSRT values typically range from 100 to 500 milliseconds, with lower scores (faster reaction time) indicating better inhibitory control.

    Measured: Baseline, Week 5 (post-intervention)

  3. Change from baseline in Mental Set Shifting

    Assessed using the Wisconsin Card Sorting Test (WCST). The outcome include the number of categories achieved, perseverative errors and set-loss errors. Higher number of categories achieved, lower perseverative errors and set-loss errors indicate better cognitive flexibility and set-shifting ability.

    Measured: Baseline, Week 5 (post-intervention)

  4. Change from baseline in Short-Term Memory

    Assessed using the Corsi Block-Tapping Task. The outcome is Corsi span score. The Corsi span is defined as the longest sequence accurately reproduced by participants. Scores range from 0 to 9 blocks, with higher scores indicating better short-term memory capacity.

    Measured: Baseline, Week 5 (post-intervention)

Secondary outcomes (4)
  1. Change in Heart Rate Variability (HRV)

    HRV will be assessed as a non-invasive marker of autonomic nervous system (ANS) flexibility and neurovisceral integration, reflecting the dynamic regulation of the prefrontal-vagal pathway. Higher HRV serves as a physiological indicator of superior executive function and emotional regulation, whereas lower values are linked to autonomic dysregulation and cognitive fatigue. Data will be captured using a validated Polar H10 chest strap and the Elite HRV application for precise R-R interval detection. Outcome measurement include time-domain indices (SDNN, RMSSD), frequency-domain measures (HF, LF, and LF/HF ratio), and non-linear metrics (SD1, SD2). Increased RMSSD and HF power will be interpreted as enhanced parasympathetic modulation, providing the physiological foundation for improved attentional control and neural efficiency.

    Measured: Baseline and Week 5 (post-intervention)

  2. Change in Posture Alignment

    1. Craniovertebral angle (CVA) Measured from a lateral-view in a relaxed standing position. Participants look forward and maintain a comfortable stance during image acquisition. The CVA is the angle between a line connecting the tragus of the ear to the C7 spinous process and a horizontal line passing through C7. A Smaller angle indicates more severe forward head posture.
    2. Acromion-to-table distance (ATD) While supine, the vertical distance between the posterior aspect of the acromion and the table surface is measured. A larger distance indicates increased rounded shoulder posture or thoracic kyphosis.

    Measured: Baseline and Week 5 (post-intervention)

  3. Change in Psychological status

    The Traditional Chinese version of Depression Anxiety Stress Scales-21 (DASS-21) will be used to assess negative emotional states including depression, anxiety, and stress. DASS-21 contains 21 items, with 7 items assigned to each subscale. Participants rate their symptoms over the past week on a 4-point scale ranging from 0 ("did not apply to me at all") to 3 ("applied to me very much or most of the time") in each question. Subscale scores are obtained by summing the 7 items and multiply by two within each domain, with higher scores indicating greater severity of emotional distress.

    Measured: Baseline and Week 5 (post-intervention)

  4. Change in Brain Activation

    Brain activation in the prefrontal cortex, primary motor cortex, supplementary motor area, and premotor cortex during tasks is assessed using functional near-infrared spectroscopy (fNIRS). The specific metric reported is the change in the concentration of oxygenated hemoglobin (HbO). Higher HbO values indicate increased regional cerebral blood flow and higher brain activation.

    Measured: Baseline and Week 5 (post-intervention)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Jun 2026
  2. Study start25 May 2026 (estimated)
  3. Primary completion1 Feb 2027 (estimated)
  4. Study completion1 Feb 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07620249
Sponsor's protocol ID
202603092RIN
Status last verified
May 2026
First submitted
11 May 2026
Last updated
2 Jun 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Publications

  • Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017 Sep 28;5:258. doi: 10.3389/fpubh.2017.00258. eCollection 2017.

    PubMed 29034226
  • Kopp B, Lange F, Steinke A. The Reliability of the Wisconsin Card Sorting Test in Clinical Practice. Assessment. 2021 Jan;28(1):248-263. doi: 10.1177/1073191119866257. Epub 2019 Aug 2.

    PubMed 31375035
  • Verbruggen F, Logan GD. Response inhibition in the stop-signal paradigm. Trends Cogn Sci. 2008 Nov;12(11):418-24. doi: 10.1016/j.tics.2008.07.005.

    PubMed 18799345
  • Yeung MK, Han YMY. Changes in task performance and frontal cortex activation within and over sessions during the n-back task. Sci Rep. 2023 Feb 27;13(1):3363. doi: 10.1038/s41598-023-30552-9.

    PubMed 36849731
  • Bianchini E, Warmerdam E, Romijnders R, Hansen C, Pontieri FE, Maetzler W. Cognitive dual-task cost depends on the complexity of the cognitive task, but not on age and disease. Front Neurol. 2022 Oct 3;13:964207. doi: 10.3389/fneur.2022.964207. eCollection 2022.

    PubMed 36313514
  • Khng KH, Lee K. The relationship between Stroop and stop-signal measures of inhibition in adolescents: influences from variations in context and measure estimation. PLoS One. 2014 Jul 3;9(7):e101356. doi: 10.1371/journal.pone.0101356. eCollection 2014.

    PubMed 24992683
  • Voss A, Schroeder R, Heitmann A, Peters A, Perz S. Short-term heart rate variability--influence of gender and age in healthy subjects. PLoS One. 2015 Mar 30;10(3):e0118308. doi: 10.1371/journal.pone.0118308. eCollection 2015.

    PubMed 25822720
  • Pinti P, Tachtsidis I, Hamilton A, Hirsch J, Aichelburg C, Gilbert S, Burgess PW. The present and future use of functional near-infrared spectroscopy (fNIRS) for cognitive neuroscience. Ann N Y Acad Sci. 2020 Mar;1464(1):5-29. doi: 10.1111/nyas.13948. Epub 2018 Aug 7.

    PubMed 30085354
  • Ferreira L, Tanaka K, Santos-Galduroz RF, Galduroz JC. Respiratory training as strategy to prevent cognitive decline in aging: a randomized controlled trial. Clin Interv Aging. 2015 Mar 20;10:593-603. doi: 10.2147/CIA.S79560. eCollection 2015.

    PubMed 25848235
  • Nazir S, Mathiyakom W, Tassawar MA, Tantisuwat A. The effect of diaphragmatic breathing and diaphragmatic mobilization on physical performance, fear of falling, and quality of life in community-dwelling older adults: A randomized controlled trial. PLoS One. 2026 Jan 5;21(1):e0339868. doi: 10.1371/journal.pone.0339868. eCollection 2026.

    PubMed 41490262
  • Katzman WB, Wanek L, Shepherd JA, Sellmeyer DE. Age-related hyperkyphosis: its causes, consequences, and management. J Orthop Sports Phys Ther. 2010 Jun;40(6):352-60. doi: 10.2519/jospt.2010.3099.

    PubMed 20511692
  • Ren Y, Cui G, Zhang X, Feng K, Yu C, Liu P. The promising fNIRS: Uncovering the function of prefrontal working memory networks based on multi-cognitive tasks. Front Psychiatry. 2022 Oct 25;13:985076. doi: 10.3389/fpsyt.2022.985076. eCollection 2022.

    PubMed 36386968
  • Tiwari R, Kumar R, Malik S, Raj T, Kumar P. Analysis of Heart Rate Variability and Implication of Different Factors on Heart Rate Variability. Curr Cardiol Rev. 2021;17(5):e160721189770. doi: 10.2174/1573403X16999201231203854.

    PubMed 33390146
  • Piper SK, Krueger A, Koch SP, Mehnert J, Habermehl C, Steinbrink J, Obrig H, Schmitz CH. A wearable multi-channel fNIRS system for brain imaging in freely moving subjects. Neuroimage. 2014 Jan 15;85 Pt 1(0 1):64-71. doi: 10.1016/j.neuroimage.2013.06.062. Epub 2013 Jun 28.

    PubMed 23810973
  • Catai AM, Pastre CM, Godoy MF, Silva ED, Takahashi ACM, Vanderlei LCM. Heart rate variability: are you using it properly? Standardisation checklist of procedures. Braz J Phys Ther. 2020 Mar-Apr;24(2):91-102. doi: 10.1016/j.bjpt.2019.02.006. Epub 2019 Feb 26.

    PubMed 30852243

Questions about this trial

What is this clinical trial studying?

A study testing thoracic expansion exercises and slow diaphragmatic breathing in people with Diaphragm Pacing, run by National Taiwan University Clinical Trial Center.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 2 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Yun Syuan Lin (+886 986161796, b11408046@ntu.edu.tw), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change from baseline in Working Memory (time frame: Baseline, Week 5 (post-intervention)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07620249, which also lists 41 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jun 2026.

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