Breathing Interventions for Relaxation: Dosing Through Extended Exhale

Not Applicable

Completed

Conditions: Healthy Adults
Stress

Interventions: Behavioral: Slow breathing

Registration Number: NCT02870868

Lead Sponsor: Vanderbilt University Medical Center

Brief Summary: Breathing exercises are categorized as a mind-body practice. One in ten adults in the U.S. use breathing exercises for health purposes. The aim of this project is to examine if different slow breathing has different physiological and psychological effects.

Detailed Description: Breathing exercises are categorized as a mind-body practice. One in ten adults in the U.S. use breathing exercises for health purposes. Slow breathing exercises are commonly used for stress reduction. Higher stress is associated with higher cardiovascular risk. Effective and standardized breathing interventions for stress reduction have not been developed or well-studied. For centuries, mind-body practitioners have proposed that, in addition to breathing slowly, extending the length of exhale relative to inhale increases the dose of relaxation. Few studies have tested this belief. The aim of this proposal is to examine if slow breathing while extending the exhale time relative to the inhale time increases physiological and psychological relaxation. The slow breathing exercises to be studied are based on breathing techniques from yoga. This is a12-week study among healthy adults randomized to daily slow breathing exercises of: (1) exhale greater than inhale versus (2) exhale equal to inhale in length. The first aim of the studies will be to compare 12 weeks of slow breathing with exhale greater than inhale on physiological stress as measured through autonomic tone. The second aim will be to compare changes in psychological stress as measured through validated stress and anxiety questionnaires. The final and third aim will be to measure the correlation between changes in physiological and psychological stress. This project will test if specific breathing techniques produce measurable and meaningful differences in stress in both healthy and disease populations. Because stress reduction is considered the major mechanism of mind-body practices, these studies will advance the field of mind-body science.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 99

Inclusion Criteria

Age 30 to 60 years
English speaking

Exclusion Criteria

Hypertension
Heart disease: history of coronary artery disease, myocardial infarction, significant valvular disease, or congestive heart failure
Diabetes
Renal disease
Anxiety disorder
Depression
Other psychiatric conditions including schizophrenia or bipolar disorder
Attention-deficit-disorder or Attention-deficit-hyperactivity disorder
Musculoskeletal condition limiting capacity to perform simple movements such as chronic lower back pain or neck pain
Pulmonary disorder (asthma, chronic obstructive lung disease, obstructive sleep apnea)
Smoker
Currently taking blood pressure medications, oral diabetic medication or insulin
Current participation in a mind-body practice/program
Current cancer other than non- melanoma skin cancer
Regular swimmer
Plays wind or brass musical instruments

After two weeks during screening period unable to:

Breathe 8 or less a minute
Breathe 3 or less breaths a minute
Practiced less than 3 times a week

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Slow breathing with exhale greater than inhale	Slow breathing	Participants randomized to slow breathing with prolonged exhale to inhale ratio received progressive increases in expiration relative to inspiration based on initial assessment until they reached a goal breath length or longest comfortable breath. Prior to performing the breathing practice, subjects in this exhale\>inhale condition performed the same yoga movements as the exhale-inhale group.
Slow breathing with exhale equal to inhale	Slow breathing	Participants randomized to slow breathing with equal inspiration and expiration received progressive increases in both inspiration and expiration over 4 weeks until they reach a goal breath length or longest comfortable breath. Goal breaths were assigned based on initial breath assessment. Prior to performing the breathing practice, participants performed a few standardized yoga movements. The purpose of movements was to prepare the subject to sit and focus on breathing. Subjects randomized to exhale=inhale will receive progressive increases in both inspiration and expiration until they reach a goal breath length. Goal breaths will be assigned based on initial breath assessment. Prior to performing the breathing practice, subjects will perform a set of standardized breathing practices. The purpose of these few breathing practices is to prepare the subject to sit and focus on breathing.

Primary Outcome Measures

Name	Time	Method
Magnitude of Change in High Frequency Heart Rate Variability	12 weeks	This is a proxy measure of parasympathetic tone. In normal healthy adults, the average value is around 600 ms\^2 (miliseconds\*miliseconds). In hypertensive adults, the average value is around 100 ms\^2. In patients with autonomic failure (who lacks parasympathetic tone), the average value is around 20 ms\^2.
Magnitude of Change in PROMIS Anxiety Scale	12-weeks	Measure of psychological stress taken at baseline before any study intervention. The scale ranges from 0 (no anxiety) to 100 (maximal anxiety). In the normal adult population, the average of the PROMIS Cooperative Group. (2011). Item banks for measuring emotional distress from the Patient-Reported Outcomes Measurement Information System (PROMIS) Anxiety score is 50. A higher score correlates with increased anxiety and a lower score correlates with lower anxiety.

Secondary Outcome Measures