Exercise as it relates to Disease/Increasing Physical Activity to Improve Sleep and Mood Outcomes for People with Insomnia

This Wikibooks fact sheet is an analysis of the article Increased physical activity improves sleep and mood outcomes in inactive people with insomnia: a randomized control trial (Hartescu, Morgan, & Stevinson, 2015). By u107992

What is the background to this research?
Insomnia is a relatively common but highly debilitating chronic mental health problem (Morin et al., 2006). Therapies for insomnia include medication, behavioural therapies including sleep restriction, cognitive behavioural therapy, relaxation, and lifestyle changes such as improved diet or physical activity. Exercise is a cost-effective and well-tolerated treatment for insomnia, with low side effects and a wide range of additional health benefits (Sattelmair et al., 2011). Previous studies have demonstrated that both high and low intensity exercise is effective for improving sleep outcomes (Yang, Ho, Chen, & Chien, 2012). However, the minimum level of physical activity that can effectively alleviate symptoms of insomnia is yet to be determined. In addition, previous physical activity trials have not controlled for daylight exposure, which may increase with higher levels of exercise and could independently affect sleep outcomes via an alternative mechanism. This trial sought to determine the independent effects of minimum standards prescribed for physical activity and light exposure on insomnia symptoms.

Where is the research from?
The study was conducted by experienced researchers at Loughborough University in the UK. The study was based at the Clinical Sleep Research unit was established in 2003 and has a strong history of research into the evidence-based management and treatments for insomnia. The first two authors (Hartescu and Morgan) have a strong track record in insomnia research. The last author was located at the School of Sport, Exercise and Health Sciences at Loughborough University and provides the expertise on exercise, with a research background in the effect of physical activity in cancer care. The authors declared they had no conflicts of interest.

What kind of research was this?
The study design was a two-arm randomised control trial (RCT). The study was of high quality, using concealed and independently conducted randomisation, intention to treat analysed, and reporting of baseline differences (there weren’t any). RCTs are the second highest level of evidence, second only to systematic reviews and meta-analyses.

What did the research involve?
The intervention began with a conditioning period (presumably to attain sufficient fitness levels) of 4 weeks followed by instructions to complete moderate physical activity for 150 minutes of exercise each week (30 minutes at least 5 days per week) over the remaining intervention period (6 months). The participants were provided with a small hip worn pedometer (step counter) and accelerometer (measured minutes of moderate-vigorous physical activity only). An Actiwatch 2 worn for 2 weeks at baseline, and at post-intervention measured light exposure.

The methodology was appropriate for the aims of the study. Blinding of condition was not possible, and often isn’t in psychological and behavioural interventions. As an illustration of this, two participants dropped out because they were unsatisfied at being randomised to the control condition. A waitlist control group may have helped alleviate dissatisfaction with group allocation, although because the intervention period was relatively lengthy (6 months), this may not have been useful. An obvious limitation of this, is that participants are clearly aware of their assigned condition.

What were the basic results?
At 6 months (post-intervention), the intervention group showed significantly reduced insomnia symptoms on the primary outcome measure, the Insomnia Severity Index (4 point mean reduction on scale 0-28), which from a clinical perspective reduced the average participant’s insomnia from ‘moderate to severe insomnia’ to ‘subthreshold insomnia’. The authors are modest in their description of the findings and report that the effects of the intervention on insomnia symptoms were “modest, but clinically significant” (Hartescu et al., 2015, p. 532)

Secondary outcomes of symptoms of depression and anxiety also showed significant improvement; however, curiously daytime sleepiness and fatigue did not improve significantly. The authors indicate that it is possible that sleep and fatigue may operate independently. Finally, there was no significant effect of condition on the amount of daylight exposure.

What conclusions can we take from this research?
Although, the potential placebo effects of knowing they were in the intervention group cannot be discounted, the intervention group (219 minutes per week) objectively completed greater levels of physical activity than the control (74 minutes per week), and adherence in the intervention group to the minimum standards of physical activity per week was high (95% of weeks for the intervention group). It is of note that depression and anxiety symptoms were also significantly reduced. These mental health problems are highly comorbid with insomnia, particularly when chronic. This demonstrates the breadth of physical and mental health problems that physical activity can be used to improve as was noted in the introduction to the research.

This paper was published quite recently; however, research into insomnia is continuing and is looking into a number of non-drug related therapies to treat insomnia. A meta-analysis published in 2015 demonstrated that exercise can have small effects on various aspects of sleep (Kredlow, Capozzoli, Hearon, Calkins, & Otto, 2015). A systematic review conducted in 2013 showed that yoga can be well tolerated and is effective in improving insomnia and sleep disturbances in cancer survivors (Mustian, 2013).

This research adds to the evidence base for the use of physical activity for reducing the symptoms of insomnia.

Practical advice
This study showed that even minimum standard levels of exercise (150 minutes per week) could improve insomnia symptoms independently of the effects of daylight exposure. Physical activity can be conducted for free (generally), and is well-tolerated with the study demonstrating high levels of adherence, which is a positive finding for its real-world application. Physical activity and also has added benefits of potentially improving other health outcomes in addition to treating insomnia. However, it is important to ensure individuals with insomnia are physically suitable and have no contraindications to participating in an exercise program.

Further information/resources
This study was conducted by researchers at Loughborough University in the UK. Their aim is to improve the understanding and evidence-based management of insomnia and chronic sleep disturbance through research and training. Information, advice and further readings can be found at their website. http://www.lboro.ac.uk/departments/ssehs/research/research-centres/research-groups/clinical-sleep-research/

Another good resource for those with insomnia and other sleep conditions is The Sleep Health Foundation (SHF). SHF aims to improve people's lives through better sleep. More information is available at http://www.sleephealthfoundation.org.au/