An interventional study of Breathing Group 1 and Breathing Group 2 in CSF Circulation, sponsored by Oregon Health and Science University. Completed at 1 site in United States. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-10-29.
Sponsored by Oregon Health and Science University · Not applicable, Interventional, and Basic science
The purpose of this research study is to determine the influence of yoga breathing practices on cerebrospinal fluid (CSF) circulation, and to find out primarily if a regular practice of 8-week yoga breathing would enhance CSF circulation as well as if the intervention would improve participant's quality of life, quality of sleep, and reduce existing stress. Participants will be randomized into two arms for different breathing practices.
The purpose of this research protocol is to determine the influence of an 8-week breathing intervention on cerebrospinal fluid (CSF) circulation among healthy participants using a non-invasive real-time phase-contrast magnetic imaging (RT-PCMRI) technique. This aim will be examined by studying the changes in each participant's pre- and post-intervention CSF flow dynamics using the non-invasive RT-PCMRI technique during two MRI scans (one before and one after the 8-week intervention).
The study protocol consists of 20 healthy participants (two groups; 10 in each group with different breathing practices) undergoing an 8-week intervention, and pre-and post-intervention outcome measures.
The two 8-week interventions will be guided by two separate certified experienced yoga teachers. Both interventions will consist of 60-minute weekly group on-site sessions (1day/week) with a 20-minute daily home sessions (in between on-site sessions; 6 days/week) using home-aid practice materials. Participants' respiration data will be objectively tracked using a wearable respiration tracker device.
96 studies on the registry are indexed under Hypoventilation; 21 are open to participants now.
This study's enrollment of 26 is below the median of 52 across 63 interventional studies indexed under Hypoventilation.
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- 18-65 years of age, able to provide their consent to be in the study, available and able to participate in study activities, who can lie in supine, able to walk 15 feet, who have no prior/current mind-body practice inducing breath awareness or training such as yoga, meditation, Ta-Chi, Qi-Gong.
Exclusion Criteria:
- Inability to provide , MRI , need for muscle relaxants or anti-anxiety drugs in order to tolerate MRI, history of neurological disorders, head trauma with loss of consciousness, craniospinal disorders, spinal injury, sleep disorders, allergic or respiratory disorders, major or uncontrolled psychiatric illness or major depression, lung and heart problems, any condition requiring the use of medication that acts on the brain like stimulants, sedatives current substance abuse issues, pregnancy or nursing.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
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A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Arm 1 will receive an 8-week intervention that consists of a set of breathing practices through 60-minute weekly group on-site sessions (1day/week) with a 20-minute daily home sessions (in between on-site sessions; 6 days/week).
Behavioral: Breathing Group 1
Arm 2 will receive an 8-week intervention that consists of slow breathing practices through 60-minute weekly group on-site sessions (1day/week) with a 20-minute daily home sessions (in between on-site sessions; 6 days/week).
Behavioral: Breathing Group 2
The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
CSF Flow Velocities
We have collected cerebrospinal fluid (CSF) flow measurements during a set of breathing practices while subjects were inside the MRI scanner. MRI-based CSF flow was quantified at the level of Foramen Magnum. Data processing included the extraction of velocity waveforms of the CSF motion ( i.e, CSF velocity in cm/s) and subsequent analysis of CSF velocities across different breathing conditions. Positive CSF velocities indicate fluid motion in the cranial (upward) direction, whereas negative velocities represent fluid motion in the caudal (downward) direction. For the registry, descriptive statistics of CSF velocities (mean and standard deviation) are reported at pre- and post-intervention for participants completing both MRI visits with analyzable CSF data (Group 1 n=7, Group 2 n=7). No inferential statistical tests or change score analyses are included in the registry submission; all reported results are descriptive only.
Time frame: Baseline (pre-intervention) and post-intervention (after 8 weeks).
Systolic and Diastolic Blood Pressure
Systolic and diastolic blood pressure were measured participants seated at rest at pre- and post-intervention visits.
Time frame: Baseline (pre-intervention) and post-intervention (after 8 weeks).
Body Mass Index (BMI)
BMI was collected at pre- and post-intervention visits, and was calculated as weight in kilograms divided by height in meters squared (kg/m²).
Time frame: Baseline (pre-intervention) and post-intervention (after 8 weeks).
Daily Home Practice Frequency
Average breathing practice frequency were measured using a wearable respiration tracker to objectively evaluate home practice throughout the intervention: frequency (days/week). Preliminary analysis estimated mean frequency (days/week) across participants. Onsite class sessions were excluded.
Time frame: 8 weeks (daily home practice over the course of 8-week intervention).
Daily Home Practice Duration
Average breathing practice duration were measured using a wearable respiration tracker to objectively evaluate home practice throughout the intervention: duration (in minute). Preliminary analysis estimated mean duration (minutes) across participants. Onsite class sessions were excluded.
Time frame: 8 weeks (daily home practice over the course of 8-week intervention).
| Milestone | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Started | 11 | 10 |
| Completed | 9 | 7 |
| Not completed | 2 | 3 |
| Withdrew: Withdrawal by subject | 2 | 3 |
We have collected cerebrospinal fluid (CSF) flow measurements during a set of breathing practices while subjects were inside the MRI scanner. MRI-based CSF flow was quantified at the level of Foramen Magnum. Data processing included the extraction of velocity waveforms of the CSF motion ( i.e, CSF velocity in cm/s) and subsequent analysis of CSF velocities across different breathing conditions. Positive CSF velocities indicate fluid motion in the cranial (upward) direction, whereas negative velocities represent fluid motion in the caudal (downward) direction. For the registry, descriptive statistics of CSF velocities (mean and standard deviation) are reported at pre- and post-intervention for participants completing both MRI visits with analyzable CSF data (Group 1 n=7, Group 2 n=7). No inferential statistical tests or change score analyses are included in the registry submission; all reported results are descriptive only.
| cm/s | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Pre-intervention maximum (cranially directed) CSF velocity during natural breathing | 1.36 ± 0.27 | 1.31 ± 0.23 |
| Post-intervention maximum (cranially directed) CSF velocity during natural breathing | 1.48 ± 0.42 | 1.15 ± 0.25 |
| Pre-intervention minimum (caudally directed) CSF velocity during natural breathing | -1.92 ± 0.51 | -1.73 ± 0.41 |
| Post-intervention minimum (caudally directed) CSF velocity during natural breathing | -1.68 ± 0.47 | -1.84 ± 0.45 |
| Pre-intervention maximum (cranially directed) CSF velocity during slow breathing | 1.76 ± 0.62 | 1.48 ± 0.37 |
| Post-intervention maximum (cranially directed) CSF velocity during slow breathing | 1.56 ± 0.45 | 1.35 ± 0.43 |
| Pre-intervention minimum (caudally directed) CSF velocity during slow breathing | -2.15 ± 0.63 | -1.68 ± 0.48 |
| Post-intervention minimum (caudally directed) CSF velocity during slow breathing | -1.80 ± 0.37 | -1.94 ± 0.66 |
| Pre-intervention maximum (cranially directed) CSF velocity during deep abdominal breathing | 2.02 ± 0.64 | 1.64 ± 0.43 |
| Post-intervention maximum (cranially directed) CSF velocity during deep abdominal breathing | 1.79 ± 0.57 | 1.43 ± 0.37 |
| Pre-intervention minimum (caudally directed) CSF velocity during deep abdominal breathing | -2.12 ± 0.61 | -1.68 ± 0.47 |
| Post-intervention minimum (caudally directed) CSF velocity during deep abdominal breathing | -1.90 ± 0.47 | -1.75 ± 0.55 |
| Pre-intervention maximum (cranially directed) CSF velocity during deep diaphragmatic breathing | 1.88 ± 0.38 | 2.00 ± 1.31 |
| Post-intervention maximum (cranially directed) CSF velocity during deep diaphragmatic breathing | 1.61 ± 0.58 | 1.42 ± 0.33 |
| Pre-intervention minimum (caudally directed) CSF velocity during deep diaphragmatic breathing | -2.14 ± 0.61 | -2.23 ± 1.32 |
| Post-intervention minimum (caudally directed) CSF velocity during deep diaphragmatic breathing | -1.97 ± 0.256 | -1.80 ± 0.46 |
| Pre-intervention maximum (cranially directed) CSF velocity during deep chest breathing | 2.02 ± 0.62 | 1.49 ± 0.47 |
| Post-intervention maximum (cranially directed) CSF velocity during deep chest breathing | 1.58 ± 0.45 | 1.51 ± 0.44 |
| Pre-intervention minimum (caudally directed) CSF velocity during deep chest breathing | -2.03 ± 0.42 | -1.73 ± 0.56 |
| Post-intervention minimum (caudally directed) CSF velocity during deep chest breathing | -1.74 ± 0.54 | -1.77 ± 0.53 |
Systolic and diastolic blood pressure were measured participants seated at rest at pre- and post-intervention visits.
| mmHg | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Pre-intervention systolic blood pressure | 128.11 ± 16.07 | 117.71 ± 7.99 |
| Post-intervention systolic blood pressure | 125.62 ± 4.55 | 118.29 ± 7.99 |
| Pre-intervention diastolic blood pressure | 80.22 ± 4.08 | 66.29 ± 4.15 |
| Post-intervention diastolic blood pressure | 76.00 ± 3.46 | 63.43 ± 4.15 |
BMI was collected at pre- and post-intervention visits, and was calculated as weight in kilograms divided by height in meters squared (kg/m²).
| kg/m² | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Pre-Intervention BMI | 25.33 ± 1.66 | 24.33 ± 1.56 |
| Post-Intervention BMI | 25.16 ± 1.57 | 24.46 ± 1.56 |
Average breathing practice frequency were measured using a wearable respiration tracker to objectively evaluate home practice throughout the intervention: frequency (days/week). Preliminary analysis estimated mean frequency (days/week) across participants. Onsite class sessions were excluded.
| days/week | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Daily Home Practice Frequency | 5.00 ± 0.82 | 5.43 ± 0.80 |
Average breathing practice duration were measured using a wearable respiration tracker to objectively evaluate home practice throughout the intervention: duration (in minute). Preliminary analysis estimated mean duration (minutes) across participants. Onsite class sessions were excluded.
| minute | Breathing Group 1 | Breathing Group 2 |
|---|---|---|
| Daily Home Practice Duration | 21.80 ± 2.27 | 20.22 ± 0.54 |
Collected over 12 weeks per participant ( 2-week-pre intervention, 8-week intervention, and 2-week post-intervention).. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Breathing Group 1 | 0/11 (0%) | 0/11 (0%) | 0/11 (0%) |
| Breathing Group 2 | 0/10 (0%) | 0/10 (0%) | 0/10 (0%) |
The baseline analysis population included all 21 participants who completed enrollment and provided pre-intervention data (Active n=11, Control n=10). These participants are represented in the baseline characteristics table.
| Age, Categorical(Participants) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 11 | 10 | 21 |
| >=65 years | 0 | 0 | 0 |
| Age, Continuous(Years) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| Mean | 35.09 ± 14.46 | 34.00 ± 14.05 | 34.57 ± 13.92 |
| Sex: Female, Male(Participants) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| Female | 5 | 5 | 10 |
| Male | 6 | 5 | 11 |
| Race (NIH/OMB)(Participants) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 2 | 2 | 4 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 1 | 1 | 2 |
| White | 7 | 5 | 12 |
| More than one race | 0 | 1 | 1 |
| Unknown or Not Reported | 1 | 1 | 2 |
| Region of Enrollment(participants) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| United States | 11 | 10 | 21 |
| Body Mass Index (BMI)(kg/m²) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| Mean | 25.15 ± 4.62 | 25.89 ± 5.23 | 25.50 ± 4.81 |
| Systolic Blood Pressure(mmHg) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| Mean | 126.45 ± 14.87 | 122.70 ± 21.23 | 124.67 ± 17.81 |
| Diastolic Blood Pressure(mmHg) | Breathing Group 1 | Breathing Group 2 | Total |
|---|---|---|---|
| Mean | 78.09 ± 11.95 | 68.60 ± 13.18 | 73.57 ± 13.16 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Jul 2019 to primary completion in Nov 2019, 4 months.
Results were first posted in Oct 2025, 5 years 11 months after primary completion.
Of 35 non-industry interventional studies with no phase under Hypoventilation, half reached primary completion within 15 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 26. This study's 4 months is below that.
Counting every sponsor, half of 35 studies reached it within 15 months; a quarter within 5 and three quarters within 26.
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This study is completed, as verified in Oct 2025. You cannot join it, but the record below documents what was studied.
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