Exercise as it relates to Disease/Response to vigorous exercise in a PTSD diagnosed military and first responder population

This Wikipage is a critique of the research article "Acute Physiological Responses Following a Bout of Vigorous Exercise in Military Soldiers and First Responders with PTSD: An Exploratory Pilot Study" by Kathryn E Speer, Stuart Semple and Andrew J McKune. This Wikipage was prepared as an assessment for the unit Health, Disease and Exercise at the University of Canberra, Semester 2, 2022.

What is the background to the research?
Post-Traumatic Stress Disorder (PTSD) is a mental illness, classified in the Diagnostic and Statistical Manual of Mental Disorders 5-TR (DSM-5-TR) with the following criteria:


 * The person was exposed to death, threatened death, actual or threatened serious injury, or actual or threatened sexual violence.
 * The traumatic event is persistently re-experienced.
 * Avoidance of trauma-related stimuli after the trauma.
 * Negative thoughts or feelings that began or worsened after the trauma.
 * Trauma-related arousal and reactivity that began/worsened after the trauma.
 * Symptoms last more than 1 month.
 * Symptoms create distress or functional impairment.
 * Symptoms are not due to medication, substance use, or other illness.

Additionally, PTSD sufferers often experience isolation, distrust, relationship difficulties, and communication issues. A cadre at a higher risk of developing PTSD during their lifetime are past and present members of the armed services, police, paramedics, firefighters and other first responders. Persistent exposure to traumatic events is an unfortunate and unavoidable result of these roles. Cumulatively these factors limit the ability or likelihood of sufferers engaging in suitable levels of physical activity; increasing the risk of co-morbidities such as cardiovascular disease, type II diabetes, metabolic syndrome, concurrent mental illnesses, substance abuse, and self-harm/suicide. This study was a pre-cursor to larger studies aimed at determining the effect exercise has on these and other physiological and inflammatory responses to PTSD.

Where is this research from?
The authors, Kathryn Speer, Stuart Semple and Andrew J McCune, are from the Discipline of Sport and Exercise Science at the University of Canberra (UC). All authors have a significant library of published literature in the field of sport and exercise science in relation to mental health issues.

What kind of research was this?
This research project was a pilot study. The aim of a pilot study is to test criteria such as designs, strategies, methodology, measures and participant compliance, whilst also fine-tuning hypotheses and identifying problem areas. The study may also obtain information to guide calculation of sample size for the main project, as well as statistical measures including mean and standard deviation (SD).

A sample of 8 males, aged 20 to 75 years, either currently serving/retired armed forces personnel or first responders were recruited for this study. The sample consisted of a control group without PTSD and a group with a PTSD diagnosis, both consisting of equal participants (n=4).

What did the research involve?
Researchers recruited through local advertising and flyers at hospitals, clinics, and mental health support services. Candidates were compared against exclusion criteria and completed the Exercise and Support Science Australia (ESSA) adult pre-exercise screening tool and the Depression, Anxiety and Stress Scale (DASS). Cardiorespiratory fitness was measured and physiological and saliva samples were obtained. On the day of testing participants completed a DASS questionnaire prior to a vigorous boxing session. Additional samples and DASS questionnaires were undertaken 30 minutes post exercise, and again at 24- and 48-hours post-exercise.

The goal of this study, in comparison to others in the field, was to identify physiological changes, such as heart rate and inflammatory markers. Whilst psychological changes were measured, they received less attention. This study focused on qualitative data over quantitative, a common theme in pilot/feasibility studies, whereby the researchers seek further information to enhance research quality, validity, and reliability. Transition from pilot studies to full research projects may involve adjustment of participants, and recruitment, to increase retention rate particularly in the control sample.

One question in relation to data collection in this study relates to group diversity. The participants were all male, with varying exposures either resulting in a PTSD diagnosis or no official diagnosis. Participants fell across a broad age group of 55 years, which may increase potential for a variance in exposed trauma type and length of time symptoms have been displayed. It is unknown if this related to a poor participant recruitment response, or whether breadth of age will be adjusted in the full trial. Additionally, the researchers do not provide insight to pre-existing treatment for participants, either psychologically or pharmacologically, whether diagnosed with PTSD or otherwise. Current medications and psychological co-morbidities are mentioned however there is no explanation for the non-consideration of these variables.

What were the basic results?
Vagal activity, a branch of the parasympathetic nervous system (PNS), is responsible for regulating various internal organs, including heart and respiratory rate. One of the prominent findings from this study was that vagal activity had not returned to pre-exercise levels 48 hours post-exercise in the PTSD group, whereas healthy/athletic individuals almost immediately saw a rise in vagal activity at cessation of exercise.

DASS questionnaire responses were relatively consistent across the control group at all stages, however the PTSD group showed a decline from pre-exercise results at the 24 hr. mark, with results returning to pre-exercise levels for the most part.

What conclusions can we take from this research?
The outcome of this study is consistent with similar studies investigating the effect of exercise on PTSD. The researchers surmise the lower vagal recovery/response observed in PTSD sufferers may be an indicator of cardiovascular morbidity and mortality risk. Proposed future research identified in this study relates to the binding of hormones to the vagus nerve and the subsequent response.

This study was insular, in that all exercise was conducted under supervision, in a purpose-built facility without external stressors. Other studies had participants continue exercise programs as part of their normal routine to gauge not only the psychological and physiological outcomes, but also the practicality and adaptability of those programs.

Although the results of this and other studies are promising and appear to confirm the inverse relationship between PTSD and exercise, additional research, including a subsequent trial based on this pilot study, would offer additional validation. Both the PTSD and control groups were very small and nondiverse, but significantly different in terms of age, trauma, and other variables. Additional studies should aim to diversify the sample of the population; in both control and testing group; duration, location, and intensities.

Practical advice
Research conducted indicates that exercise at moderate to high-intensity may have the best results in symptom reduction. It is important to note that the trials conducted in this study were undertaken under the supervision of professionals at a purpose-built laboratory. Given this, it is important that anyone considering an exercise program seek medical advice prior to commencement. The study provides no practical advice on commencement or implementation of any specific or generic exercise program, due to the nature and purpose of the study.

Further information/resource
The following websites provide additional information on PTSD:

Beyond Blue Australia https://www.beyondblue.org.au/the-facts/anxiety/types-of-anxiety/ptsd

Phoenix Australia https://www.phoenixaustralia.org/your-recovery/

Black Dog Institute https://www.blackdoginstitute.org.au/resources-support/post-traumatic-stress-disorder/