Exercise as it relates to Disease/Resistance training and depression: does intensity matter?

The following is a critique of the research article: Singh NA, Stavrinos TM, Scarbek Y, Galambos G, Liber C, Fiatarone Singh MA, et al.

A Randomized Controlled Trial of High Versus Low Intensity Weight Training Versus General Practitioner Care for Clinical Depression in Older Adults.

The Journals of Gerontology: Series A.

Created as an assessment requirement for the University of Canberra unit: Health Disease and Exercise (August–September 2020).

What is the background to this research?
Exercise has a beneficial effect in the treatment of depression, although there is little knowledge of how to prescribe exercise for symptoms of depression and its dose response relationship.

The research article in focus improves our understanding of the intensity in which resistance training should be performed for depressed older adults to help alleviate symptoms of depression.

The older-adult demographic is of significance to this research as they are less tolerant to antidepressants. Experiencing higher rates of adverse events. Antidepressants are associated with negative side-effects, some particularly concerning for older-adults include: Depression is a major risk-factor of falls, a study showing high prevalence (66.7%) of depression in those hospitalized due to falls, antidepressants contributing to this.
 * Sedation, dizziness, tachycardia and cognitive decline.

A less 'toxic' treatment option is of interest. Exercise providing a promising alternative with minimal side-effects.

Where is the research from?
The research took place in the Central Sydney area, NSW Australia.

Nalin A. Singh is the author of this article. Singh is an Associate Professor at his exercise and rehabilitation practice The Centre for Strong Medicine. He has a reputable portfolio of published literature, in the area or exercise and the older-adult population.published articles.

While the researchers did not mention any sponsorship, the perspective of the paper is to promote exercise which could be a reporting bias. The efficacy of traditional depression treatment is not negated, rather an alternative option is suggested.

What kind of research was this?
The study design was an 8-week Randomized-Controlled-Trial (RCT).

Generally, RCTs are deemed to be a powerful influence on research and our understanding of the relationship between interventions on subject populations. This article has used the controlled study design to make a case for the use of exercise as a depression intervention.

Available literature suggests exercise is moderately effective when compared to a control but no more effective than traditional treatment. Although, some information is conflicting. A 2015 meta-analysis of exercise's effect on depressed older-adults concluded that exercise may serve as a "feasible additional intervention". Stating that all types of exercise can show a significant effect. Whereas another meta-analysis expressed its lack of confidence in exercise as a depression treatment. Inferring that bias is present in trials reporting positive effects.

Further studies with larger sample populations are needed to better understand exercise as a depression intervention, particularly on resistance training's dose-response for depression.

What did the research involve?
Sixty (n=60) depressed older-adults were allocated to 1 of 3 intervention groups: (protocols supplied below)
 * High intensity resistance training (HIGH),
 * Low intensity resistance training (LOW), or
 * General care by usual GP (GP).

Participants were monitored over 8 weeks by a psychiatrist that was unaware of the intervention allocation. The psychiatrist assessed their level of depression by specific outcome measures. After 8-weeks the participant's results were compared to baseline (starting depression). Change in depression ratings help to understanding the effect of different exercise intensities when compared to traditional GP treatment.
 * The trial's design was well controlled ensuring blinding of the psychiatrist completing the assessments was maintained throughout.
 * The use of well validated outcome measures was also a key strength of the study, for example the GDS is validated for the subject population and is sensitive to change, allowing us to correlate improvements with intervention effectiveness.
 * The sample size (n=60) is small. A larger group of participants would have added weight to the results.
 * The possibility of bias is also high in this study, which may lead to an exaggerated report of positive effects.

What were the basic results?
All groups improved in self-rated GDS and therapist assessed HRSD over time. HIGH was significantly more effective than the other groups in reducing GDS ratings (p<0.006), HRSD scores also improved more in HIGH, although not deemed statistically significant (p=0.14). The discussion is largely focused on the high intensity resistance training aspect of the trial. Mostly reporting the results of that group, emphasizing improvements in muscle strength, quality of life and sleep, although all groups experienced significant improvements in these areas. Excluding muscle strength, of which is expected when compared to a sub-optimal training regimen and a non-exercise intervention. Nevertheless, the improvements help discern the effects of all interventions.

What conclusions can we take from this research?
Resistance training has potential to help alleviate depression in older adults. Although further research is required to better understand what is optimal. This study creates a case that resistance training should be performed at a high intensity to help treat depression in older-adults. Suggesting a dose-response and the possibility of an intensity threshold to see improved symptoms of depression. This study alone is insufficient to conclude this indefinitely and no recent studies added to this argument. Studies suggest a dose-response of aerobic exercise for depression, favouring higher intensities. However, there is no consensus of its prescription for depression either.

Practical advice
Meeting the physical activity guidelines is supported overwhelmingly with evidence for health and longevity. This should be a starting point for healthy individuals. While there are no guidelines for resistance training in depressed older adults specifically. The American College of Sports Medicine (ACSM) has general recommendations for older adults which would serve as a useful guideline when starting an exercise regimen.

Exercise should be prescribed based on the individual's own capabilities and screening is advised before engaging in a new program. (see links below for professional help)

Further information/resources
Depression in older people - Black Dog Institute

Exercise and Depression - Black Dog Institute

[https://order.nia.nih.gov/sites/default/files/2017-07/workout-to-go_508.pdf Limited exercise experience? - try this!]

An enjoyable read that might get you moving!

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