Trial Outcomes & Findings for Influence of Yogic Breathwork on CSF Circulation (NCT NCT03858309)
NCT ID: NCT03858309
Last Updated: 2025-10-29
Results Overview
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.
COMPLETED
NA
26 participants
Baseline (pre-intervention) and post-intervention (after 8 weeks).
2025-10-29
Participant Flow
Participant milestones
| Measure |
Breathing Group 1
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Overall Study
STARTED
|
11
|
10
|
|
Overall Study
COMPLETED
|
9
|
7
|
|
Overall Study
NOT COMPLETED
|
2
|
3
|
Reasons for withdrawal
| Measure |
Breathing Group 1
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Overall Study
Withdrawal by Subject
|
2
|
3
|
Baseline Characteristics
Influence of Yogic Breathwork on CSF Circulation
Baseline characteristics by cohort
| Measure |
Breathing Group 1
n=11 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=10 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
Total
n=21 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
11 Participants
n=5 Participants
|
10 Participants
n=7 Participants
|
21 Participants
n=5 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Age, Continuous
|
35.09 Years
STANDARD_DEVIATION 14.46 • n=5 Participants
|
34.00 Years
STANDARD_DEVIATION 14.05 • n=7 Participants
|
34.57 Years
STANDARD_DEVIATION 13.92 • n=5 Participants
|
|
Sex: Female, Male
Female
|
5 Participants
n=5 Participants
|
5 Participants
n=7 Participants
|
10 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
6 Participants
n=5 Participants
|
5 Participants
n=7 Participants
|
11 Participants
n=5 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Asian
|
2 Participants
n=5 Participants
|
2 Participants
n=7 Participants
|
4 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Black or African American
|
1 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
2 Participants
n=5 Participants
|
|
Race (NIH/OMB)
White
|
7 Participants
n=5 Participants
|
5 Participants
n=7 Participants
|
12 Participants
n=5 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
1 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
2 Participants
n=5 Participants
|
|
Region of Enrollment
United States
|
11 participants
n=5 Participants
|
10 participants
n=7 Participants
|
21 participants
n=5 Participants
|
|
Body Mass Index (BMI)
|
25.15 kg/m²
STANDARD_DEVIATION 4.62 • n=5 Participants
|
25.89 kg/m²
STANDARD_DEVIATION 5.23 • n=7 Participants
|
25.50 kg/m²
STANDARD_DEVIATION 4.81 • n=5 Participants
|
|
Systolic Blood Pressure
|
126.45 mmHg
STANDARD_DEVIATION 14.87 • n=5 Participants
|
122.70 mmHg
STANDARD_DEVIATION 21.23 • n=7 Participants
|
124.67 mmHg
STANDARD_DEVIATION 17.81 • n=5 Participants
|
|
Diastolic Blood Pressure
|
78.09 mmHg
STANDARD_DEVIATION 11.95 • n=5 Participants
|
68.60 mmHg
STANDARD_DEVIATION 13.18 • n=7 Participants
|
73.57 mmHg
STANDARD_DEVIATION 13.16 • n=5 Participants
|
PRIMARY outcome
Timeframe: Baseline (pre-intervention) and post-intervention (after 8 weeks).Population: The analysis population included participants who completed both MRI visits and had analyzable CSF flow data (n=14; Group 1=7, Group 2=7). Pre- and post-intervention peak CSF velocities (maximum cranially directed and minimum caudally directed) during breathing practices were summarized in absolute units (cm/s) as mean and standard deviation.
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.
Outcome measures
| Measure |
Breathing Group 1
n=7 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=7 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
CSF Flow Velocities
Pre-intervention minimum (caudally directed) CSF velocity during natural breathing
|
-1.92 cm/s
Standard Deviation 0.51
|
-1.73 cm/s
Standard Deviation 0.41
|
|
CSF Flow Velocities
Post-intervention minimum (caudally directed) CSF velocity during natural breathing
|
-1.68 cm/s
Standard Deviation 0.47
|
-1.84 cm/s
Standard Deviation 0.45
|
|
CSF Flow Velocities
Pre-intervention maximum (cranially directed) CSF velocity during slow breathing
|
1.76 cm/s
Standard Deviation 0.62
|
1.48 cm/s
Standard Deviation 0.37
|
|
CSF Flow Velocities
Post-intervention maximum (cranially directed) CSF velocity during slow breathing
|
1.56 cm/s
Standard Deviation 0.45
|
1.35 cm/s
Standard Deviation 0.43
|
|
CSF Flow Velocities
Pre-intervention minimum (caudally directed) CSF velocity during slow breathing
|
-2.15 cm/s
Standard Deviation 0.63
|
-1.68 cm/s
Standard Deviation 0.48
|
|
CSF Flow Velocities
Post-intervention minimum (caudally directed) CSF velocity during slow breathing
|
-1.80 cm/s
Standard Deviation 0.37
|
-1.94 cm/s
Standard Deviation 0.66
|
|
CSF Flow Velocities
Pre-intervention maximum (cranially directed) CSF velocity during deep abdominal breathing
|
2.02 cm/s
Standard Deviation 0.64
|
1.64 cm/s
Standard Deviation 0.43
|
|
CSF Flow Velocities
Pre-intervention maximum (cranially directed) CSF velocity during deep diaphragmatic breathing
|
1.88 cm/s
Standard Deviation 0.38
|
2.00 cm/s
Standard Deviation 1.31
|
|
CSF Flow Velocities
Pre-intervention maximum (cranially directed) CSF velocity during natural breathing
|
1.36 cm/s
Standard Deviation 0.27
|
1.31 cm/s
Standard Deviation 0.23
|
|
CSF Flow Velocities
Post-intervention maximum (cranially directed) CSF velocity during natural breathing
|
1.48 cm/s
Standard Deviation 0.42
|
1.15 cm/s
Standard Deviation 0.25
|
|
CSF Flow Velocities
Post-intervention maximum (cranially directed) CSF velocity during deep abdominal breathing
|
1.79 cm/s
Standard Deviation 0.57
|
1.43 cm/s
Standard Deviation 0.37
|
|
CSF Flow Velocities
Pre-intervention minimum (caudally directed) CSF velocity during deep abdominal breathing
|
-2.12 cm/s
Standard Deviation 0.61
|
-1.68 cm/s
Standard Deviation 0.47
|
|
CSF Flow Velocities
Post-intervention minimum (caudally directed) CSF velocity during deep abdominal breathing
|
-1.90 cm/s
Standard Deviation 0.47
|
-1.75 cm/s
Standard Deviation 0.55
|
|
CSF Flow Velocities
Post-intervention maximum (cranially directed) CSF velocity during deep diaphragmatic breathing
|
1.61 cm/s
Standard Deviation 0.58
|
1.42 cm/s
Standard Deviation 0.33
|
|
CSF Flow Velocities
Pre-intervention minimum (caudally directed) CSF velocity during deep diaphragmatic breathing
|
-2.14 cm/s
Standard Deviation 0.61
|
-2.23 cm/s
Standard Deviation 1.32
|
|
CSF Flow Velocities
Post-intervention minimum (caudally directed) CSF velocity during deep diaphragmatic breathing
|
-1.97 cm/s
Standard Deviation 0.256
|
-1.80 cm/s
Standard Deviation 0.46
|
|
CSF Flow Velocities
Pre-intervention maximum (cranially directed) CSF velocity during deep chest breathing
|
2.02 cm/s
Standard Deviation 0.62
|
1.49 cm/s
Standard Deviation 0.47
|
|
CSF Flow Velocities
Post-intervention maximum (cranially directed) CSF velocity during deep chest breathing
|
1.58 cm/s
Standard Deviation 0.45
|
1.51 cm/s
Standard Deviation 0.44
|
|
CSF Flow Velocities
Pre-intervention minimum (caudally directed) CSF velocity during deep chest breathing
|
-2.03 cm/s
Standard Deviation 0.42
|
-1.73 cm/s
Standard Deviation 0.56
|
|
CSF Flow Velocities
Post-intervention minimum (caudally directed) CSF velocity during deep chest breathing
|
-1.74 cm/s
Standard Deviation 0.54
|
-1.77 cm/s
Standard Deviation 0.53
|
SECONDARY outcome
Timeframe: Baseline (pre-intervention) and post-intervention (after 8 weeks).Population: Participants who completed both pre- and post-intervention visits and had systolic/diastolic blood pressure data collected at both time points.
Systolic and diastolic blood pressure were measured participants seated at rest at pre- and post-intervention visits.
Outcome measures
| Measure |
Breathing Group 1
n=9 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=7 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Systolic and Diastolic Blood Pressure
Pre-intervention systolic blood pressure
|
128.11 mmHg
Standard Deviation 16.07
|
117.71 mmHg
Standard Deviation 7.99
|
|
Systolic and Diastolic Blood Pressure
Post-intervention systolic blood pressure
|
125.62 mmHg
Standard Deviation 4.55
|
118.29 mmHg
Standard Deviation 7.99
|
|
Systolic and Diastolic Blood Pressure
Pre-intervention diastolic blood pressure
|
80.22 mmHg
Standard Deviation 4.08
|
66.29 mmHg
Standard Deviation 4.15
|
|
Systolic and Diastolic Blood Pressure
Post-intervention diastolic blood pressure
|
76.00 mmHg
Standard Deviation 3.46
|
63.43 mmHg
Standard Deviation 4.15
|
SECONDARY outcome
Timeframe: Baseline (pre-intervention) and post-intervention (after 8 weeks).Population: The analysis population for BMI included participants who completed both pre- and post-intervention visits and had weight and height data collected at both time points.
BMI was collected at pre- and post-intervention visits, and was calculated as weight in kilograms divided by height in meters squared (kg/m²).
Outcome measures
| Measure |
Breathing Group 1
n=9 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=7 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Body Mass Index (BMI)
Pre-Intervention BMI
|
25.33 kg/m²
Standard Deviation 1.66
|
24.33 kg/m²
Standard Deviation 1.56
|
|
Body Mass Index (BMI)
Post-Intervention BMI
|
25.16 kg/m²
Standard Deviation 1.57
|
24.46 kg/m²
Standard Deviation 1.56
|
SECONDARY outcome
Timeframe: 8 weeks (daily home practice over the course of 8-week intervention).Population: Twelve participants (6 in each group) who completed the 8-week intervention and had usable respiration tracker data. Participants without trackers or with missing data due to technical issues were excluded.
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.
Outcome measures
| Measure |
Breathing Group 1
n=6 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=6 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Daily Home Practice Frequency
|
5.00 days/week
Standard Deviation 0.82
|
5.43 days/week
Standard Deviation 0.80
|
SECONDARY outcome
Timeframe: 8 weeks (daily home practice over the course of 8-week intervention).Population: Twelve participants (6 in each group) who completed the 8-week intervention and had usable respiration tracker data. Participants without trackers or with missing data due to technical issues were excluded.
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.
Outcome measures
| Measure |
Breathing Group 1
n=6 Participants
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).
Breathing Group 1: The 8-week breathwork intervention incorporates a set of breathing practices under the guidance of a certified yoga teacher.
|
Breathing Group 2
n=6 Participants
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).
Breathing Group 2: The 8-week breathwork intervention incorporates a set of slow breathing practices under the guidance of a certified yoga teacher.
|
|---|---|---|
|
Daily Home Practice Duration
|
21.80 minute
Standard Deviation 2.27
|
20.22 minute
Standard Deviation 0.54
|
Adverse Events
Breathing Group 2
Breathing Group 1
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Selda Yildiz, PhD
Oregon Health & Science University (OHSU)
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place