Breathwork and Stress: Investigating the Mechanisms of Action and Effectiveness of Breathing Interventions in Modulating the Psychophysiological Response to Acute Stress Test
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 发起方
- 入组人数
- 120
- 试验地点
- 2
- 主要终点
- Change in Root Mean Square of Successive (RMSSD)
研究概览
简要总结
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.
Participants will:
- 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.
详细描述
This three-arm randomized controlled trial is designed to investigate whether the therapeutic benefits of slow-paced breathing stem from specific physiological mechanisms (cardiorespiratory resonance) or non-specific psychological factors, such as attention, expectancy, and structured relaxation.
The study directly compares resonant-frequency breathing against a structurally identical sham intervention and a passive control group.
Experimental Protocol:
The study utilizes the Maastricht Acute Stress Test (MAST) as a highly structured and validated laboratory stressor to capture the dynamic psychophysiological response to acute distress.
The protocol consists of the following phases:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
盲法说明
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
入排标准
- 年龄范围
- 18 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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/monthly 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
研究组 & 干预措施
Spontaneous Breathing (Control)
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.
Coherent Breathing (6 bpm)
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.
干预措施: Coherent Breathing (6 bpm) (Behavioral)
Sham Breathing (15 bpm)
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.
干预措施: Sham Breathing (15 bpm) (Behavioral)
结局指标
主要结局
Change in Root Mean Square of Successive (RMSSD)
时间窗: 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.
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.
Change in PNS Index
时间窗: 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.
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.
Change in Salivary Cortisol Concentration
时间窗: 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.
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).
Change in STAI-State score
时间窗: 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.
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.
Change in Mean HR
时间窗: 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 measured in beats per minute (bpm). This serves as a fundamental indicator of physiological arousal and autonomic nervous system activity.
次要结局
- 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.)
- Change in Standard Deviation of NN intervals (SDNN)(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.)
- SNS index during Intervention Blocks(Average score 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.)
- Change in LF power log (ln LF)(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 Log-transformed High-Frequency HRV Power (ln HF)(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.)
- PNS 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.)
- PNS index during Intervention Blocks(Average score 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.)
- Change in Systolic Blood Pressure (SBP)(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 Mental Tension (VAMS)(At Baseline (0 minutes), and at approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.)
- Change in Subjective Calmness (VAMS)(At Baseline (0 minutes), and at approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.)
- Change in Subjective Relaxation (VAMS)(At Baseline (0 minutes), and at approximately 25, 45, 60, and 75 minutes after Baseline during the single experimental session on Day 3.)