Effects of High Ventilation Breathwork With Retention (HVBR) on Mental Health and Wellbeing: A Randomised Placebo-controlled Trial
Phase: NA
Conditions: Stress, Anxiety, Depressive Symptoms, Mental Wellbeing, Positive Affect, Negative Affect, Sleep-Related Impairment
Sponsor: University of Sussex

Study Protocol  
 
Effects of high ventilation breathwork with retention on mental 
health and wellbeing: A randomised placebo-controlled trial 
(NCT06064474) 
 
Guy William Fincham, Elissa Epel, Alessandro Colasanti, Clara Strauss, Kate Cavanagh 
 
Document date: October 09, 2023  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Background & rationale 
There has been an unprecedented surge in public/scientific interest in a style of breathwork 
that incorporates hyperventilation (high ventilation) with breath-holds (retention). This 
technique has similarities to Tibetan Tummo meditation and Yogic Pranayama but has been 
popularised in the West by the Wim Hof Method (Kox et al., 2014). Despite emerging 
research there are no well-controlled studies exploring effects of high ventilation breathwork 
with retention (HVBR) on mental health and wellbeing. We plan to complete the first robust 
randomised-controlled trial (RCT) comparing HVBR (20 minutes/day) for three weeks to a 
well-designed placebo (paced breathing at 15 breaths/min with retentions). The metric of 
15b/min aligns with guidance from the British Journal of Nursing, Royal College of 
Physicians and Johns Hopkins Medicine which state that the average, healthy rate should 
range from: 12-20, 12-18 and 12-16b/min, respectively. 
 
Slow breathwork has received most research attention so far; in our recent meta-analysis 
(Fincham et al., 2023) we found significant small-medium effects, showing breathwork was 
associated with lower subjective stress (primary outcome), anxiety and depression 
(secondary outcomes) compared to non-breathwork controls. For the primary outcome, 10 
and only 2 studies respectively comprised slow and fast breathwork; these were of moderate 
and high risk of bias, suggesting more robust tests of their potential effects are needed. 
Nonetheless, fast breathwork may offer potential therapeutic benefit as temporary 
voluntarily induced stress has been suggested as, and could possibly be, beneficial for health 
(Petraskova Touskova et al., 2022). High-intensity physical exercise can improve health by 
inducing a sympathetic response (stress) initially, subsequently followed by adaptation. 
Similarly, HVBR may induce short-term stress that can improve mental health and 
provisional evidence has shown it may confer beneficial therapeutic effects regarding 
perceived stress (Kopplin & Rosenthal, 2022). While increasing stress seemingly mitigates 
the improved health claims of HVBR, it might be elucidated more clearly through the notion 
of hormesis, an adaptive response to states of moderate bodily stress (Mattson, 2008). The 
key, perhaps, is that it is not done reflexively (i.e., responsive hyperventilation during a panic 
attack), but is performed deliberately in a controlled manner (i.e., hyperventilation during an 
intentional breathwork practice); and only five min/day of HVBR for four weeks has also 
been associated with improvements on state anxiety along with positive and negative affect 
(Balban et al., 2023). For example, exercise is voluntarily induced and thus is a different 
stressor to reactive states in response to negative stressors in life. Both RCTs of Kopplin and 
Rosenthal (2022) and Balban et al. (2023) display positive effects of HVBR on mental health 
outcomes, however such findings are limited by the quality of trial design and study methods 
used. For example, neither included a placebo control, making it difficult to establish for 
these studies whether the interventions had specific active effects on mood beyond 
attention/expectation effects. Further, more research is needed to gauge the safety profile of 
fast breathwork. Whilst our meta-analysis did not find negative effects directly attributed to 
breathwork, only six studies in total (for all outcomes) out of 26 actively reported on this. 
Thus, we will actively do so. 
 
The theoretical rationale for our study is: Identifying if HVBR exerts effects on mental health 
and wellbeing related outcomes via a well-designed RCT within a young (18-39), healthy 
general population. The appropriate placebo used here may help disentangle effects of the 
breathwork intervention (Sevoz-Couche & Laborde, 2022), if any. The practical rationale is: 
Using data collected to help develop time- and cost-effective remote interventions for 
lowering stress and improving wellbeing. Studies included in our meta-analysis were deemed 
as being at moderate or high risk of bias, including all RCTs using fast breathwork, hence we 
plan to complete the first low risk-of-bias fast breathwork RCT. We wish to share findings 
through publication in a reputable open-access journal to inform practice and hopefully 
benefit others. 
 
 

Objectives & endpoints 
The main question our study attempts to address is: Does HVBR lead to improved mental 
health and wellbeing? Participants will be randomised to a guided audio of HVBR (four 
rounds with longer retentions) or placebo breathwork (15b/min with four shorter retentions) 
for 20min/day, for 21 days, both pre-recorded by a trained breathwork facilitator, delivered 
remotely. Participants will be asked whether negative effects (both short- and long-term) 
occurred. The study will be conducted online through Prolific (all data will be anonymous). 
We will collect self-reports of mental health and wellbeing pre-post and at three-week follow-
up. 
 
Research Questions 
Primary research question  
- 
Does HVBR lead to improved subjective stress (primary outcome) in comparison to 
an active placebo control in a general population adult sample at post-intervention 
(primary timepoint)? 
Secondary research questions  
- 
Does HVBR lead to improved subjective stress in comparison to an active placebo 
control in a general population adult sample at follow-up? 
- 
Does HVBR lead to improved subjective anxiety in comparison to an active placebo 
control in a general population adult sample at: a) post-intervention, b) follow-up? 
- 
Does HVBR lead to improved subjective depression in comparison to an active 
placebo control in a general population adult sample at: a) post-intervention, b) 
follow-up? 
- 
Does HVBR lead to improved subjective mental wellbeing in comparison to an active 
placebo control in a general population adult sample at: a) post-intervention, b) 
follow-up? 
- 
Does HVBR lead to improved subjective sleep-related impairment in comparison to 
an active placebo control in a general population adult sample at: a) post-
intervention, b) follow-up? 
- 
Does HVBR lead to improved subjective positive affect in comparison to an active 
placebo control in a general population adult sample: a) immediately after the first 
session of breathwork, b) at post-intervention. 
- 
Does HVBR lead to improved subjective negative affect in comparison to an active 
placebo control in a general population adult sample: a) immediately after the first 
session of breathwork, b) at post-intervention. 
Exploratory Hypotheses  
Additionally, we want to see if pre-post changes are correlated with a) adherence (amount of 
breathwork practice, i.e., is there a dose response?), and b) credibility and expectancy of the 
breathwork intervention given. We would expect both greater adherence (in the HVBR 
practice arm) and credibility/expectancy to be associated with greater improvements on the 
outcome measures listed. If there are significant differences between groups on 
credibility/expectancy then covariance analysis will be explored, to test whether differences 
between groups in credibility/expectancy are accounting for any measured differences in 
outcomes at post-intervention.  
 
 

Methods  
Participants  
200 people (100 per group) will be recruited. We will also select the balanced sample filter 
option on Prolific so as to distribute the study evenly across gender. A moderate effect size, 
statistical power and significance level of 0.50, 0.80 and 0.05, respectively, requires a 
sample of 128 participants (64 per group). PsyDAO, a decentralised organisation funding 
research at the intersection of psychedelics and mental health, provided funding for 
participant payments for a sample size of 200 participants, so this was the largest sample 
possible, and also allows for potential attrition. The two previous published RCTs of Balban 
et al. (2023) and Kopplin and Rosenthal (2022) had final samples of N=108 (4 groups; 
HVBR condition n=33) and N=86 participants (4 groups; HVBR condition n=20), 
respectively. The former study was adequately powered statistically, but the latter was not 
(actually required a sample size of 100). 
The (self-assessed) inclusion criteria are as follows: -Comfortable with holding breath, -
Comfortable with faster breathing, -Willing to only practice breathwork in safe environment, 
lying down in soft area (i.e., bed, sofa, carpet/mat), and always away from water and hard 
ground, -Willing to only practice the breathwork away from large meals (i.e., before or one 
hour after) and bedtime (i.e., at least one hour before if practicing in evening), -Have access 
to headphones. The following pre-screeners on Prolific will also be set so only those eligible 
on Prolific will see the study: 18-39 years of age (18 is the automatic minimum age on 
Prolific), Located/living in UK, Fluent in English, approval rate of 98% and at least 20 
previous submissions (as recommended by Prolific to increase retention and reduce dropout 
rates in longitudinal and multi-part studies). 
The comprehensive (self-assessed) exclusion criteria are as follows: -Hypotension or 
hypertension (low or high blood pressure), -History of respiratory or cardiovascular/heart 
problems or disease, -History of fainting or syncope, -Epilepsy or seizures, -History of panic 
disorder or panic attacks, Cerebral aneurysm, -Have had problems with prior breathwork 
sessions (i.e., fainting), -Pregnancy or think one might be pregnant, trying to get pregnant, or 
are breastfeeding, -Any problems which affect one's ability to pace their breathing (i.e., 
active/chronic respiratory infection including blocked nose/cough/cold/fever, etc.), 
breathlessness, abnormally slow breathing (bradypnea), or abnormally fast breathing 
(tachypnoea), -Any other physical/mental health conditions or current life events which 
impair or affect one’s ability to engage in activities involving breath control, -Taking any 
regular medication other than the contraceptive pill, including medications to reduce blood 
pressure (i.e., Ramipril or other ACE-inhibitors), beta blockers (i.e., Propranolol), 
antidepressants, anxiolytics, or any other psychotropic medications. 
Outcome measures  
All outcomes (primary, secondary, other) are mentioned below. 
Pre-post intervention and follow-up questionnaires will be self-completed by participants 
online via the survey platform Qualtrics, which will be linked to Prolific. Three short scales 
will be used to measure trait outcomes of mental health, wellbeing and sleep-related 
impairment at these timepoints (baseline/pre-intervention, post-intervention, three-week 
follow-up): the Depression Anxiety Stress Scale (DASS-21) (Lovibond, & Lovibond, 1995), 
Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) (Ng Fat et al., 2017), and 
PROMIS Item Bank v. 1.0 - Sleep-Related Impairment - Short Form 4a (PROMIS-4a) 
(Hanish, Lin-Dyken & Han, 2017). The primary outcome will be stress (measured using the 
DASS-21 stress subscale), and the primary timepoint will be post-intervention (three weeks 

post-randomisation). The secondary outcomes will include: anxiety and depression (from 
DASS-21), mental wellbeing (SWEMWBS) and sleep-related impairment (PROMIS-4a). 
State measures of positive and negative affect using the Positive and Negative Affect 
Schedule (PANAS-20) (Watson, Clark & Tellegen, 1988) (secondary outcomes) will also be 
completed during the baseline survey. Immediately after starting the breathwork (first 
session of breathwork), participants will be asked about the credibility and expectancy of the 
intervention randomly allocated to them to assess if the intervention and placebo are seen as 
equally credible and thus merit equal expectation of benefit. This will be measured using the 
Credibility/Expectancy Questionnaire (CEQ-6), which is another secondary outcome. The 
PANAS-20 will also be completed once at this timepoint, to gauge a sense of state change due 
to the breathwork, in addition to once more at post-intervention. The last secondary 
outcomes, which will be measured post-intervention, are: negative side effects (to judge the 
safety and tolerability profile of the breathwork) and adherence to protocol (number of times 
participants self-reported practicing breathwork out of the 21 days assigned). Other 
outcomes include general sentiment towards the protocol (i.e., positive, negative, neutral) 
and open-ended questions on participants overall experiences of the protocol and/or study 
period. Pre-intervention, simple demographics (Age, Gender and Ethnicity) will be collected 
and, at follow-up, participants will be asked if they can guess which condition they were 
allocated to (to tentatively see if blinding was successful—see Procedure section). 
Primary outcome measure 
1. Subjective stress (DASS-21 stress subscale) 
Secondary outcome measures:  
2. Subjective anxiety (DASS-21 anxiety subscale)  
3. Subjective depressive symptoms (DASS-21 depression subscale)  
4. Subjective mental wellbeing (SWEMWBS)  
5. Subjective sleep-related impairment (PROMIS-4a)  
[All of above outcomes measured pre-post-follow-up] 
6. Subjective positive affect (PANAS-20 positive affect subscale). Measured pre-
intervention, after first breathwork session, and post-intervention. 
7. Subjective negative affect (PANAS-20 negative affect subscale). Measured pre-
intervention, after first breathwork session, and post-intervention. 
8. Self-reported credibility and expectancy of protocol (CEQ-6). Measured after 
completing first session of breathwork. 
9. Negative side effects due to protocol (whether participants experienced 
unpleasant/unwanted a) short-term effects, and/or  b) lasting bad effects from the 
breathwork, to gauge safety and tolerability). Measured post-intervention.  
10. Self-reported adherence to breathwork protocol (number of sessions participants 
self-report practicing out of 21 days assigned). Measured post-intervention.  
Other—Overall experience, Hypothesis guessing, Attention checks  
Optional questions on participants' perspectives and overall experience of the protocol (post-
intervention) / study-period (follow-up), and if they can correctly guess which condition they 
were allocated to (follow-up). Lastly, The DASS-21, SWEMWBS, PROMIS-4a, and PANAS-
20 will all have one attention-check question in them to ensure participants are completing 
the surveys properly. 
 

 
Procedure 
Participants will be recruited entirely online via the research study platform Prolific to gain a 
general population sample. Participants will see a title of the study, a description (describing 
what participants will be doing in the study), including the participant information sheet and 
consent form with all key information that will help them to decide if they wish to 
participate. It will also be specified that the study requires audio. Participants will see all this 
information before they choose to take part in the study, allowing them to make an informed 
choice as to whether they'd like to participate. Again, pre-screeners on Prolific will also be set 
so only those eligible on Prolific will see the study on the platform: 18-39, Located/living in 
UK, Fluent in English, approval rate of 98% and at least 20 previous submissions (as 
recommended by Prolific to increase retention and reduce dropout rates in longitudinal and 
multi-part studies). Participants will be paid to complete the surveys (30min total for all 
parts) at the hourly rate of 9GBP/hour (4.50GBP in total) which is deemed as a good, 
recommended amount by Prolific. We unfortunately do not have funds to pay participants to 
complete the daily breathwork (classed as low effort activity by Prolific). Daily reminder 
messages will be sent through Prolific to practice breathwork over the 21 days and keep a 
record of number of times practiced. All participant data will be anonymous (only Prolific 
user IDs will be seen). No identifiable personal information will be collected. When the first 
(baseline/pre-intervention) survey is complete we will get the participant IDs of the relevant 
Prolific participants. We will then invite these participants to the subsequent surveys (e.g., 
post-intervention) using a custom allowlist on Prolific (only those on the allowlist will see the 
study on their Prolific profile). As we have two conditions and want to keep these conditions 
consistent between surveys, separate identical surveys for each condition are set up. 
However, only one pre-intervention survey is needed as Qualtrics supports allocation to 
conditions from one URL. Messages will also be sent through Prolific to complete post-
intervention and follow-up questionnaires when required. 
Intervention & Comparator  
Participants in the intervention group will be randomised to a guided audio of HVBR pre-
recorded by a trained breathwork facilitator for ~20min/day over 21 days (three weeks). This 
will be delivered remotely online through audio link, and comprises evocative music and four 
rounds of hyperventilation with four separate retentions (breath holds), progressively 
increasing in length (from ~45seconds up to ~90 seconds). The average number of HVBR 
rounds used is usually 3-4, so four rounds were chosen for the intervention group. The 
duration of ~20min was deemed as a manageable time for participants, and several studies 
(ranging from days to weeks) on meditation have shown benefit can be derived from this 
low-to-moderate length of practice. 
Participants in the control group will be randomised to a guided audio of placebo ‘sham’ 
HVBR pre-recorded by a trained breathwork facilitator for ~20min/day over three weeks. 
This will be delivered remotely through audio link, comprising music and four rounds of 
paced breathing at 15b/min (equal inhale:exhale without pauses) with four separate 
(shorter) retentions, slightly increasing in length (from ~10secs to ~25secs). The metric of 
15b/min is in line with guidance from the British Journal of Nursing, Royal College of 
Physicians, and Johns Hopkins University which state that the average, healthy rate should 
range from: 12-18, 12- 20, and 12-16b/min, respectively.  
Randomisation & blinding  
The type of study is participant blinded RCT with assessor blinded data collection (that is, 
assessor is not present for data collection which is self-completed by the participant on a 
survey software platform). After completing the pre-intervention survey, participants will be 

randomly assigned, via the online survey software Qualtrics using block randomisation (1:1), 
to receive either the intervention (HVBR), or placebo (15b/min). Participants will be blinded 
to their intervention (concealment)—the study is referred to as the Sussex Fast Breathwork 
Study and the technique of breathwork will be referred to as 'rhythmic breathing' in both the 
active intervention and placebo control breathwork audios, in an attempt to blind 
participants to the intervention being used. 
Safety & ethical considerations 
This study has been approved by the Research Ethics Committee at the University of Sussex 
Sciences & Technology C-REC (reference: ER/GF221/5).  
 
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