Exercise as it relates to Disease/The effects exercise has on individuals diagnosed with chronic primary insomnia

This is a critique of the journal article titled “Effects of moderate aerobic exercise training on chronic primary insomnia”

What is the background to this research?

 * Chronic Primary Insomnia (CPI) is defined as prolonged difficulty with initiation and maintenance of sleep. Characteristics of CPI include non-restorative sleep, hyperarousal, and impaired mental and physical function such as; inferior working memory, impaired concentration, and an overall poor quality of life. Literature has hypothesised CPI as a collective pathway via interchangeable imbalances between hyperarousal and sleep inducing brain activity, encouraged through psychosocial stressors causing irregular sleeping patterns and decreased cognitive behaviour. Epidemiological literature associated CPI with other mental disorders, the most common being depression. This is evident in longitudinal studies as 40% of the depressed population have CPI symptoms. Previous literature has concluded that CPI is the most common sleeping disorder with its prevalence worldwide being 10-15%, if accounting for acute insomnia the prevalence rises to 50% of the population. Literature has also found that CPI is predominant in individuals over the age of 45 years, along with an increasing risk in Females.
 * Although CPI is the most common sleeping disorder and can work in conjunction with other disorders it is predominantly left untreated, resulting in a problematic issue at large on quality of life. Those whom do seek treatment are commonly prescribed drug therapy through sleep medication. Sleep medication is not recommended for long-term usage as there is a likelihood of potential side effects and is often expensive.
 * Using exercise as a non-pharmacological way to treat CPI along with other psychosocial diseases is becoming more prevalent as a cost effective and easily accessed treatment for antidepressant effects. Specification on type of diseases and exercise needs addressing further.

Where is the research from?

 * The research was conducted in São Paulo, Brazil. It is based on 19 sedentary individuals with CPI. The mean age of individuals being 45 ± 1.9 years.
 * The data for this study was collected over six months in 2011.
 * The authors of this study are derived from a large pool of professors and physicians. All whom have been involved in numerous publications, Marco Tûlio De Mello himself having over 400. Giselle Soares Passos specialises in medicine, sport and exercise, and psycho-neuroendocrinology. She has many years of experience in nonpharmacologic treatment for chronic insomnia.
 * The participants of this study did not include those with CPI whom are physically active, limiting generalisation of findings towards CPI as whole.

What kind of research was this?

 * This research was a randomized trial, as participants were randomised into either a morning or late afternoon exercise group.
 * The aim of the study was to determine the influence long-term aerobic training has on sedentary individuals with CPI, specifically on their subjective sleep, quality of life and mood. Secondarily assessing whether exercising in the morning or afternoon influenced the effects of the exercise and whether changes in sleep were accompanied with changes in mood.
 * The research data relied heavily on self-reports such as questionaries and sleep dairies, this influencing the validity of results due to response bias.

What did the research involve?

 * The participants whom met the selection criteria were required to keep record of their sleep every morning when they woke in a sleep dairy for 1-week. They also completed a SF-60 and POMS questionnaire prior commencing the intervention. The intervention consisted of a 6-week aerobic exercise training protocol of three days a week for 50-minutes on a treadmill as well as 5-minute warm up and cool down, this was implemented to both groups. Completion resulted in another 1-week sleep diary and both questionaries.
 * Intensity and environment were both controlled and monitored enhancing reliability of the study.
 * Limitations include the exercise protocol itself. Exercise was only completed on a treadmill, in a lab and only for 60minutes questioning the generalisation of results outside of these variables. Sleep diaries and questionaries were also only conducted before and after exercise none during, this effecting the reliability and variability of results. Although participants were randomised into two different groups there was no control group for further reliability and variability. The use of only sedentary participants concludes that generalisations cannot be made to those with CPI whom are already physically active.

What were the basic results?

 * The main results of the study indicated that there was a significant improvement in latency sleep quality, sleep onset and the feeling of ‘well-rested’ in the morning following both exercise conditions.
 * The questionaries revealed a significant decrease in tension-anxiety, depression and overall mood disturbance, as well as a significant increase in numerous quality of life characteristics.
 * There was no significant difference between either morning or night conditions.
 * Overall the 6-week exercise intervention had a positive effect on individuals with CPI assisting with both improvements in sleep and other psychological factors.

What conclusions can we take from this research?

 * The conclusion the authors suggested in this study was that long-term aerobic exercise is positively associated with individuals with CPI in numerous psychological aspects and fields in their life.
 * The conclusion I drew from this study agrees with the authors conclusion however, less generalised. Initially I concluded that 60-minutes of aerobic exercise three times a week has a significant positive impact on previously sedentary individuals with CPI in all aspects of their lifestyle not just their sleeping patterns. Although there are limitations towards generalising these findings to other types of exercise and individuals with CPI as a whole, results are consistent with other research, displaying that people with disturbed sleep significantly benefit from exercise training. Whilst it is clear that there are limitations within this study towards generalisations of results the authors conclusions can be supported by previous evidence, altering my conclusion to be the same.
 * Further research into specificity of individuals with CPI characteristics and lifestyles is needed, to determine if exercise is beneficial for everyone with CPI.

Practical advice

 * Individuals with CPI should understand the important of exercise daily and the associated benefits that come with it. This study demonstrated its positive effect towards treatment of individuals with CPI and opens a pathway for treating other disorders/ problematic lifestyle challenges.
 * Exercise as an applaudable treatment for CPI is inexpensive, easily accessible and more importantly provides further benefits in all aspects of quality of life, both physically and psychologically.
 * This research concluded with positive findings, yet limited control over validity and reliability. Researchers interested in expanding in this area of research need to address exercises suitable for the individual’s interest/lifestyle, increasing adherence of the intervention being maintained over a longer period of time. This would also assist on identifying whether other fields of exercise produce the same affect towards CPI symptoms such as; resistance training, sports, yoga, outdoor walking etc. Studies on broader individuals with CPI need addressing such as; advance fitness levels, younger cohorts, or individuals whom are injured or have long term impaired mobility to assist in generalisation of exercise as a profound treatment.

Further information/ resources

 * Kalmbach DA, Cuamatzi-Castelan AS, Tonnu CV, Tran KM, Anderson JR, Roth T, et al. Journal of Nat Sci Sleep, 10 (2018), pp. 193–201 Retrieved via Pubmed
 * Riemann D, Spiegelhalder K, Feige B, Voderholzer U, Berger M, Perlis M, et al. Journal of Sleep Medicine, 14 (2010), pp. 19–31 Retrieved via Pubmed
 * Fact sheet on insomnia: https://sleepaustralia.com.au/docs/Insomnia-Fact-Sheet-Sleep-Australia.pdf
 * https://www.beyondblue.org.au/
 * https://au.reachout.com/articles/insomnia
 * https://www.sleepoz.org.au/