None listed
Conditions
Brief summary
Anxiety disorders are the most common mental health disorders in New Zealand. One effective intervention for anxiety is use of exercise to help reduce symptoms, however the mechanisms of action are not yet known. This project aims to understand how exercise treatment for anxiety is related to changes in breathing perception, as an impaired ability to monitor bodily state has been proposed to exist within anxiety. We will therefore employ breathing tasks in a randomised controlled trial, measuring participants with significant levels of anxiety (screened from the population) both before and after 8 weeks of either exercise or a control intervention (stretching). These breathing tasks measure a number of important factors, such as perceptual accuracy and self-awareness, symptom reporting, and how an individual learns about their breathing within a changing environment. Participants will additionally partake in a safe and non-invasive brain imaging scan (magnetic resonance imaging, MRI) either side of their intervention. A control group of low anxiety individuals will also partake in the first experimental sessions. These datasets will allow us to apply state-of-the-art computational models of perception, investigating how anxiety can interrupt the brain’s processing of internal bodily states, and how exercise may target these disruptions.
Interventions
Measurement sessions before and after intervention:
Two sets of measurements will be performed within a 4 hour session (including breaks) and 1.5 hour session. The first session (4 hours) will involve completing a set of behavioural tasks that consist of answering questions about emotions and body perceptions, two tasks that involve breathing through a sterile system to detect changes in breathing effort, as well as a visual detection task and emotion recognition task (both performed on a comput
Measurement sessions before and after intervention: Two sets of measurements will be performed within a 4 hour session (including breaks) and 1.5 hour session. The first session (4 hours) will involve completing a set of behavioural tasks that consist of answering questions about emotions and body perceptions, two tasks that involve breathing through a sterile system to detect changes in breathing effort, as well as a visual detection task and emotion recognition task (both performed on a computer). One of the breathing tasks will be performed while participants lie in a magnetic resonance imaging (MRI) scanner. The second session (1.5 hours) will involve measurements of resting physiology (e.g. heart rate and breathing rate at rest), lung function tests, physiological and perceptual responses to an inhalation of elevated carbon dioxide, and an incremental exercise test on a bicycle ergometer. The two measurement sessions will take place prior to the randomisation into the study arms, and both of these sessions will then be repeated following 8 weeks of the intervention. Arm 1: Exercise intervention Participants with moderate anxiety will be randomised into the exercise or control arms. If entered into the exercise arm, participants will come to the School of Physical Education, Sport and Exercise Sciences on Union Street 2-3 times per week for 8 weeks to participate in supervised small-group exercise training sessions. Exercise training sessions will be prepared and led by a trained member of the study team, and will consist of a mixed intensity exercise program using a range of exercise modalities (such as stationary exercise cycle, treadmill, body weight exercises etc.), with modality options incorporated to accommodate needs of individual participants. Sessions will be progressed in accordance with international best practice (guidelines set out by Exercise and Sports Science Australia, ESSA), beginning with 2 sessions per week and increasing to 3 sessions with progression. Each exercise session will be up to 45 minutes in duration, and intensity level will be assessed in each session using linear rating scales from 0 to 10 (maximal) for each of 5 measures: exertion, breathlessness intensity, anxiety of breathing, leg discomfort and anxiety of leg discomfort. Participants will be monitored at all times to minimise any injury or health risks, and will be pre-screened prior to inclusion in the study using the Physical Activity Readiness Questionnaire (PAR-Q+). Session attendance checklists will be used to record any absences. Arm 2: Control intervention If participants are randomised into the control arm, they will complete a matched number of sessions (2-3 times per week for 8 weeks) that consist of a stretching protocol. Participants will be invited to complete these sessions in supervised small-group sessions conducted at the School of Physical Education, Sport and Exercise Sciences, but will additionally have the option to complete any sessions at home following guided instructions. Stretching sessions will be prepared and led by a trained member of the study team, and will comply with international best practice (guidelines set out by Exercise and Sports Science Australia, ESSA). beginning with 2 sessions per week and increasing to 3 sessions with progression. Each stretching session will be up to 45 minutes in duration, and will be targeted to be conducted at a low intensity. Exercise intensity level will also be assessed for each session using linear rating scales from 0 to 10 (maximal) for each of 5 measures: exertion, breathlessness intensity, anxiety of breathing, leg discomfort and anxiety of leg discomfort. Session attendance checklists will be used to record any absences, in conjunction with participant reports if any sessions are completed at home. Once participants have completed the control arm of the study, they will be offered the opportunity to join an exercise training group for a further 8 weeks, to allow all members of the study the option of undergoing the exercise training intervention.
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
Male or female aged between 18 and 45 years Ability to provide written and informed consent Ability to adhere to the study protocol Spielberger trait anxiety score of greater than or equal to 40 (for moderate anxiety participants) OR less than or equal to 30 (for cross-sectional low anxiety controls) Engaged in minimal organised sport or fitness activity (less than or equal to 1-2 per week of low-moderate intensity exercise for the last 6 months or more)
Exclusion criteria
Evidence of severe acute or chronic medical disorders, including a neurological disorder, current or past history of a severe brain injury or severe respiratory disorder e.g. severe asthma, chronic obstructive pulmonary disease etc. Past or current diagnoses of schizophrenia, bipolar disorder, drug addiction or psychosis Colour blindness Female patients who are pregnant or breastfeeding Current significant suicidal ideation Participants must be free of recreational drug and alcohol use at the time of testing Presence of implanted cardiac pacemakers, hearing aids, insulin pumps or neurostimulators; intracranial metal clips; or metallic bodies in the eye (MRI safety) Significant levels of smoking or vaping (more than once per week) Any regular medication (except the oral contraceptive pill for women) Contraindication to engaging in a progressive exercise program, as determined from a validated health-screening questionnaire (PAR-Q+).
Outcome results
None listed