Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12625000771459
Ethics application status
Approved
Date submitted
17/02/2025
Date registered
21/07/2025
Date last updated
21/07/2025
Date data sharing statement initially provided
21/07/2025
Type of registration
Retrospectively registered

Titles & IDs
Public title
The Effects of Brief Muscle Relaxation and Breathing Exercises on Anxiety and Perception of Breathing
Scientific title
The Effects of Brief Progressive Muscle Relaxation and Breathing Exercises on Anxiety and Respiratory Interoception in Individuals with Sub-Clinical Levels of Anxiety
Secondary ID [1] 313967 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
State Anxiety 336693 0
Respiratory Interoception 336694 0
Condition category
Condition code
Mental Health 333194 333194 0 0
Anxiety
Respiratory 334445 334445 0 0
Normal development and function of the respiratory system
Neurological 334446 334446 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
There were two intervention groups, Progressive Muscle Relaxation (PMR) and Breathing Exercises (BE), and one control group (CON; see Comparator/ control treatment section). Participants were randomly allocated into one of the groups and listened to the allocated group audio-clip.

Progressive Muscle Relaxation
- Audio-clip prerecorded by researcher of 14 minute 34 second duration administered to participants individually which consisted of instructions to guide individuals to purposefully manipulate their body to tense and relax different muscle groups (for example, instructions to clench and unclench their fists to tense and relax their arm muscles, pointing their toes up to tense their calf muscles). Administered once via headphones at the venue of the experimental session, and under direct observation to ensure adherence to the intervention.

Breathing Exercise
- Audio-clip prerecorded by researcher of 14 minute 32 second duration administered to participants individually which consisted of instructions to guide individuals through two breathing exercises -cyclic sighing and box breathing. The cyclic sighing exercise consisted of instructions guiding participants through a 5 second inhale and a 5 second exhale, followed by a pause after the exhale - with emphasis on noticing the body's natural urge to breath before returning to normal breathing rate. The box breathing exercise involved instructions that gradually worked participants up to inhaling for 5 seconds, holding the breath for 5 seconds, exhaling for 5 seconds, and holding again for 5 seconds. This audio was administered once via headphones at the venue of the experimental session, and under direct observation to ensure adherence to the intervention.
Intervention code [1] 330558 0
Treatment: Other
Comparator / control treatment
Providing two pre-recorded audio-clips, of 14 minute 40 second and 14 minute 25 second duration respectively, administered to participants individually to allow participants the choice to select their preferred topic. These audios consisted of informative content adapted from podcasts without any relaxation-based instructions to change one’s breathing rate or muscle tone: 1) The impact of birth order of personality development (loosely based off podcast Stuff You Should Know; Clark & Bryant, 2023) and 2) The functions of dreams (loosely based off podcast Unexplainable; Hassenfeld, 2022). Administered via headphones at the venue of the experimental session.
Control group
Active

Outcomes
Primary outcome [1] 340759 0
State anxiety
Timepoint [1] 340759 0
Pre-intervention, immediately post-intervention
Primary outcome [2] 340760 0
Anxiety Sensitivity (fear of anxiety-related consequences)
Timepoint [2] 340760 0
Pre-intervention, immediately post-intervention
Primary outcome [3] 340761 0
Fear of anxiety-related physical symptoms
Timepoint [3] 340761 0
Pre-intervention, immediately post-intervention
Secondary outcome [1] 445005 0
Change in inspiratory pressure from the unrestricted to restricted breath in each trial
Timepoint [1] 445005 0
Pre-intervention, immediately post-intervention
Secondary outcome [2] 445006 0
Confidence ratings obtained after each trial
Timepoint [2] 445006 0
Pre-intervention, immediately post-intervention

Eligibility
Key inclusion criteria
- Aged 18 years and older.
- Non-smoker
- No experience using progressive muscle relaxation and/ or breathing exercises within a clinical context
- At least moderate levels of trait anxiety as indicated by Spielberger State-Trait Anxiety Inventory – Trait Version (with a total score between 40 and 80)
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
- Severe acute or chronic medical, neurological, or mental health disorders.
- Current or historical respiratory difficulties (i.e., asthma, Chronic Obstructive Pulmonary Disease).
- Current suicidal thoughts.
- Current use of medication.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation was concealed (central randomisation by computer)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A sample size calculation demonstrates that to achieve 90% power using a ANCOVA for three intervention groups, 63 participants are required to detect a moderate effect size (f = 0.25) with a conservative false positive rate of 0.01. Furthermore, to ensure that adequate power (at least 80%) is reached for the study, data collection was to continue until at least 51 participants (17 in each group) were completed (to account for any dropouts).

ANCOVA run as primary analysis for anxiety questionnaire scores and interoceptive data
- Including initial checking for assumptions of linearity, normality, homogeneity of regression slopes and variances, and outlier values. Considerations for transformations, removal of outliers, and/or use of alternative statistical analyses approaches upon violation of assumptions where appropriate.
- Post-hoc testing as required upon significant effects.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
9/08/2023
Date of last participant enrolment
Anticipated
Actual
28/11/2023
Date of last data collection
Anticipated
Actual
28/11/2023
Sample size
Target
63
Accrual to date
Final
63
Recruitment outside Australia
Country [1] 26893 0
New Zealand
State/province [1] 26893 0
Dunedin

Funding & Sponsors
Funding source category [1] 318464 0
University
Name [1] 318464 0
Department of Psychology, University of Otago
Country [1] 318464 0
New Zealand
Primary sponsor type
Individual
Name
Dr Olivia Harrison (University of Otago, Department of Psychology)
Address
Country
New Zealand
Secondary sponsor category [1] 320864 0
Individual
Name [1] 320864 0
Phoebe Chin (University of Otago, Department of Psychology)
Address [1] 320864 0
Country [1] 320864 0
New Zealand
Other collaborator category [1] 283445 0
Individual
Name [1] 283445 0
Dr Bruce Russell (University of Otago, Department of Pharmacy)
Address [1] 283445 0
Country [1] 283445 0
New Zealand
Other collaborator category [2] 283446 0
Individual
Name [2] 283446 0
Faye Gorman (University of Otago, Department of Psychology)
Address [2] 283446 0
Country [2] 283446 0
New Zealand
Other collaborator category [3] 283447 0
Individual
Name [3] 283447 0
Fraser Beck (Optimal Health Model Ltd.)
Address [3] 283447 0
Country [3] 283447 0
New Zealand
Other collaborator category [4] 283448 0
Individual
Name [4] 283448 0
Sabine Wollenberg (University of Otago, Department of Psychology)
Address [4] 283448 0
Country [4] 283448 0
New Zealand
Other collaborator category [5] 283449 0
Individual
Name [5] 283449 0
Ella McLeod Edwards (University of Otago, Department of Psychology)
Address [5] 283449 0
Country [5] 283449 0
New Zealand
Other collaborator category [6] 283583 0
Individual
Name [6] 283583 0
Danielle O'Brien (University of Otago, Department of Psychology)
Address [6] 283583 0
Country [6] 283583 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 317079 0
University of Otago Human Ethics Committee (Health)
Ethics committee address [1] 317079 0
Ethics committee country [1] 317079 0
New Zealand
Date submitted for ethics approval [1] 317079 0
11/05/2023
Approval date [1] 317079 0
26/06/2023
Ethics approval number [1] 317079 0
H23/061

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 139934 0
Dr Olivia Harrison
Address 139934 0
Department of Psychology, University of Otago William James Building 275 Leith Walk, Dunedin North, Dunedin 9016
Country 139934 0
New Zealand
Phone 139934 0
+64 3 479 8818
Fax 139934 0
Email 139934 0
[email protected]
Contact person for public queries
Name 139935 0
Phoebe Chin
Address 139935 0
Department of Psychology, University of Otago William James Building 275 Leith Walk, Dunedin North, Dunedin 9016
Country 139935 0
New Zealand
Phone 139935 0
+64 22 435 1569
Fax 139935 0
Email 139935 0
[email protected]
Contact person for scientific queries
Name 139936 0
Phoebe Chin
Address 139936 0
Department of Psychology, University of Otago William James Building 275 Leith Walk, Dunedin North, Dunedin 9016
Country 139936 0
New Zealand
Phone 139936 0
+64 22 435 1569
Fax 139936 0
Email 139936 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
Yes
Will there be any conditions when requesting access to individual participant data?
Persons/groups eligible to request access:
• Researchers with sound and relevant requests

Conditions for requesting access:
• -

What individual participant data might be shared?
• All individual de-identified data for anxiety measures (STAI-S, ASI-3, BSQ) and interoception (sensitivity, bias, insight) line by line

What types of analyses could be done with individual participant data?
• IPD meta-analyses

When can requests for individual participant data be made (start and end dates)?
From:
Immediately following publication, no determined end date

To:
-

Where can requests to access individual participant data be made, or data be obtained directly?
• Access subject to approvals by researcher Phoebe Chin via email: [email protected]

Are there extra considerations when requesting access to individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.