Breathwork and Stress: Investigating the Mechanisms of Action and Effectiveness of Breathing Interventions in Modulating the Psychophysiological Response to Acute Stress Test

NCT07529379 | Recruiting

• 1 other identifier: APK.002.107.2024
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigates whether the psychophysiological benefits of breathing exercises are driven by a specific physiological rhythm (6 breaths per minute) or by the general psychological experience of performing a structured, mindful activity. Researchers aim to determine if "coherent breathing", which is hypothesized to synchronize heart and respiratory rhythms, offers unique physiological protection against stress compared to breathing at a natural pace or simple resting. The main questions it aims to answer are:

• Does slow, steady breathing at 6 breaths per minute lower physical stress markers (like heart rate variability and cortisol) better than faster, but structured breathing or just sitting still?
• Is the calming effect caused by the specific breathing rhythm or simply by performing a structured, relaxing activity? Researchers will compare three groups to see if the specific rhythm of "coherent breathing" offers unique benefits:
• Group (Interventional): Coherent Breathing: Slow breathing at 6 breaths per minute.
• Group (Sham Breathing): Regular breathing at 15 breaths per minute (matching a natural pace).
• Spontaneous Breathing (Control Group): Natural, unguided breathing.
• Complete a one-day preparation phase to become familiar with the breathing technique.
• Visit the research center for one experimental session.
• Perform their assigned breathing method before and after a stress test.
• Take the Maastricht Acute Stress Test (MAST), which involves putting a hand in cold water and doing mental math.
• Provide saliva samples and have their heart rate variability, and mood measured multiple times.

Conditions

Healthy Adult Participants; Acute Stress Reaction; Stress Biomarkers; Healthy

Keywords

Breathwork; Coherent Breathing; Resonance Breathing; Heart Rate Variability; Maastricht Acute Stress Test (MAST); Cortisol

Outcome Measures

Primary Outcomes (5)

• Change in Root Mean Square of Successive (RMSSD)

  The Root Mean Square of Successive Differences (RMSSD) measured in milliseconds (ms). This is a time-domain HRV parameter used to assess parasympathetic nervous system activity. An increase indicates higher parasympathetic activity, while a decrease indicates a stress response.

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in PNS Index

  This outcome measure is reported as a single composite score (standardized Z-score) representing the aggregated modulation of vagal activity. The final value is automatically calculated by Kubios HRV Scientific software from the mathematical combination of three specific assessments: mean RR interval, RMSSD, and the non-linear SD1 parameter, normalized against a reference database. Only the final aggregated Z-score will be reported as the endpoints for these measures. A value of 0 represents the population average; positive values indicate enhanced parasympathetic tone and recovery capacity.

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in Salivary Cortisol Concentration

  Concentration Measured via enzyme-linked immunosorbent assay (ELISA) in nmol/L. This neuroendocrine marker assesses the activation of the hypothalamic-pituitary-adrenal (HPA) axis. It is used to quantify the objective impact of the breathing intervention on the peak hormonal stress response (typically reaching maximum concentration 15-30 minutes after the stressor).

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in STAI-State score

  A validated self-report questionnaire used to measure the current intensity of anxiety, tension, and nervousness. Scores range from 20 to 80, with higher scores indicating greater subjective psychological distress.

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in Mean HR

  Mean heart rate measured in beats per minute (bpm). This serves as a fundamental indicator of physiological arousal and autonomic nervous system activity.

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

Secondary Outcomes (15)

• Change in SNS Index

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in Diastolic Blood Pressure (DBP)

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Change in Subjective Stress (VAMS)

  Measured at 5 time points: at Baseline (0 minutes), and approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.

• Mean Heart Rate (Mean HR) during Experimental Blocks

  Average heart rate measured during three 10-minute periods starting at approximately 10 minutes (First Intervention), 35 minutes (Stress Induction), and 55 minutes after Baseline during the single experimental Day 3.

• SNS Index during Stress Induction

  Average score measured during one 10-minute period starting at approximately 35 minutes (Stress Induction) after Baseline during the single experimental Day 3.

Other Outcomes (3)

• Depression Anxiety Stress Scales (DASS-21)

  At Baseline only (at the start of the Preparation Phase on Day 1).

• State-Trait Anxiety Inventory (STAI-Trait)

  At Baseline only (at the start of the experimental session on Day 3).

• Respiratory Rate (RESP)

  Average respiratory rate measured during two 10-minute periods starting at approximately 10 minutes (First Intervention) and 55 minutes (Second Intervention) after Baseline during the single experimental Day 3.

Study Arms (3)

Coherent Breathing (6 bpm)

EXPERIMENTAL

Participants perform 10 minutes of guided nasal diaphragmatic breathing at a rate of 6 breaths per minute (\~0.1 Hz). The practice involves a 5.5-second inhalation and 5.5-second exhalation phase, guided by rhythmic audio bell cues (low tone for inhale, high tone for exhale). Participants focus on abdominal movement and sensations of air flow. This intervention is performed twice: once before the acute stressor (MAST) and once during the recovery phase.

Behavioral: Coherent Breathing (6 bpm)

Sham Breathing (15 bpm)

SHAM COMPARATOR

Participants perform 10 minutes of guided nasal diaphragmatic breathing at a rate of 15 breaths per minute, which matches a natural spontaneous breathing pace. The practice involves a 2.0-second inhalation and 2.0-second exhalation phase, guided by identical rhythmic audio bell cues as the experimental arm. This arm mimics the structural and attentional components of the active intervention without inducing cardiorespiratory resonance. Performed twice: before and after the MAST protocol.

Behavioral: Sham Breathing (15 bpm)

Spontaneous Breathing (Control)

NO INTERVENTION

Participants in this passive control group sit quietly with their eyes closed for 10 minutes. They receive initial brief relaxation instructions (two deep breaths with a sigh, body muscles relaxation) but do not receive any specific rhythmic guidance, audio cues, or instructions to modulate their breathing pattern. This arm serves as a baseline to control for the natural course of the stress response and the passage of time.

Interventions

Coherent Breathing (6 bpm) BEHAVIORAL

A 10-minute session of guided nasal diaphragmatic, coherent breathing. Participants follow rhythmic audio bell cues: a low tone for a 5.5-second inhalation and a high tone for a 5.5-second exhalation. Instructions emphasize silent, gentle nasal breathing and abdominal (diaphragmatic) expansion without lifting the shoulders. Participants are asked to focus their attention on the sensations of air flow or abdominal movement throughout the session. The intervention is performed twice: before and after the stress protocol

Also known as: Resonant Breathing

Coherent Breathing (6 bpm)

Sham Breathing (15 bpm) BEHAVIORAL

A 10-minute session of guided nasal diaphragmatic breathing at a rate of 15 breaths per minute (matching a natural spontaneous pace). Participants follow identical rhythmic audio bell cues as the experimental group: a low tone for a 2.0-second inhalation and a high tone for a 2.0-second exhalation. All other instructions regarding nasal breathing, abdominal mechanics, and mindful attention are identical to the experimental group to ensure structural blinding. The intervention is performed twice: before and after the stress protocol

Also known as: Normal-paced Breathing

Sham Breathing (15 bpm)

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy adults
• Aged 18 to 60 years
• Willingness to participate in all study phases, including preparation and laboratory session.
• Professionally active individuals or university students.

You may not qualify if:

• Severe chronic diseases, including metabolic disorders (e.g., diabetes) and mental disorders.
• Cardiac arrhythmia, history of heart attacks, strokes, or heart surgery.
• Regular use of medications such as anxiolytics or beta-blockers (excluding hormonal contraception)
• Pregnancy.
• Current participation in other scientific experiments.
• Significant previous experience with breathing techniques or current independent breathwork/meditation practice (defined as regular practice for more than 7 days in total within the last 12 months).
• Professional sports practice.
• Raynaud's disease
• Inability to abstain from alcohol, caffeine, and nicotine for the required periods before the experiment

Sponsors & Collaborators

• Medical University of Bialystok: lead

Study Sites (1)

Medical University of Bialystok. Department of Physiology.

Bialystok, Podlaskie Voivodeship, 15-222, Poland

RECRUITING

Related Publications (5)

• Dick TE, Hsieh YH, Dhingra RR, Baekey DM, Galan RF, Wehrwein E, Morris KF. Cardiorespiratory coupling: common rhythms in cardiac, sympathetic, and respiratory activities. Prog Brain Res. 2014;209:191-205. doi: 10.1016/B978-0-444-63274-6.00010-2.

  PMID: 24746049 BACKGROUND

• Sevoz-Couche C, Laborde S. Heart rate variability and slow-paced breathing:when coherence meets resonance. Neurosci Biobehav Rev. 2022 Apr;135:104576. doi: 10.1016/j.neubiorev.2022.104576. Epub 2022 Feb 12.

  PMID: 35167847 BACKGROUND

• Siebieszuk A, Plonski AF, Baranowski M. Breathwork for Chronic Stress and Mental Health: Does Choosing a Specific Technique Matter? Med Sci (Basel). 2025 Aug 13;13(3):127. doi: 10.3390/medsci13030127.

  PMID: 40843749 BACKGROUND

• Smeets T, Cornelisse S, Quaedflieg CW, Meyer T, Jelicic M, Merckelbach H. Introducing the Maastricht Acute Stress Test (MAST): a quick and non-invasive approach to elicit robust autonomic and glucocorticoid stress responses. Psychoneuroendocrinology. 2012 Dec;37(12):1998-2008. doi: 10.1016/j.psyneuen.2012.04.012. Epub 2012 May 18.

  PMID: 22608857 BACKGROUND

• Shilton AL, Laycock R, Crewther SG. The Maastricht Acute Stress Test (MAST): Physiological and Subjective Responses in Anticipation, and Post-stress. Front Psychol. 2017 Apr 19;8:567. doi: 10.3389/fpsyg.2017.00567. eCollection 2017.

  PMID: 28469586 BACKGROUND

MeSH Terms

Conditions

Stress Disorders, Traumatic, Acute

Condition Hierarchy (Ancestors)

Stress Disorders, Traumatic; Trauma and Stressor Related Disorders; Mental Disorders

Central Study Contacts

Adam Siebieszuk, Master

CONTACT

+48 85 748 55 85; adam.siebieszuk@sd.umb.edu.pl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: To ensure effective blinding, participants in the two breathing groups receive identical instructions focused on nasal diaphragmatic (abdominal) breathing and mindful attention to breath sensations. Both groups are guided by 10-minute audio tracks using rhythmic bell cues (low tone for inhalation, high tone for exhalation). The only difference between these groups is the interval between the bells (5.5 s for the 6 bpm group and 2.0 s for the 15 bpm group). Participants are not informed of the specific breathing rates or the names of the techniques to maintain cognitive blinding. To ensure protocol adherence and familiarity with the rhythmic cues, all participants perform a single 10-minute practice session at home using preparatory audio track (3 s interval) 1 day before the lab intervention. The spontaneous breathing (control group) remains open-label as it involves no rhythmic guidance; they receive only initial relaxation instructions and are asked to sit quietly \& relax for 10 min
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This is a three-arm, single-blinded, randomized sham-controlled trial using a parallel assignment model. Participants are randomly assigned to one of three arms: the active intervention (coherent breathing at 6 breaths per minute), a sham-placebo control (paced breathing at 15 breaths per minute), or a passive control (spontaneous breathing). The study design is specifically intended to isolate the psychophysiological mechanisms of the 6 bpm rhythm from non-specific psychological factors, such as attention and participant expectancy.

Study Record Dates

• First Submitted: March 18, 2026
• First Posted: April 14, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): November 1, 2026
• Last Updated: April 21, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Beginning 6 months and ending 36 months following article publication.
• Access Criteria: Data will be shared with qualified researchers who provide a methodologically sound proposal. Requests should be directed to the corresponding author (adam.siebieszuk@sd.umb.edu.pl). To gain access, data requestors will need to sign a data access agreement.

Locations

PL (1)