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Unveiling the Night: How Exercise Can Alleviate Insomnia

2 April 2024


Commentary by Dr. Donald Greig

4 minute read

Those who are physically active are 55 per cent more likely to get six to nine hours of sleep a night, according to the study

Welcome to the latest edition of the HKSS newsletter dedicated to keeping you connected with your health. Our goal is to support you on your journey toward wellness by sharing the latest health insights, tips for a healthier lifestyle, and updates from our practice.


Last week, our exploration delved into the connection between plant-based diets and their positive impact on insomnia. This week, we expand our investigation to understand the advantageous effects of physical exercise. According to a study reported by The Times, engaging in exercise twice a week can enhance sleep quality, with 55% of individuals experiencing improved symptoms of insomnia. The Times article follows my commentary.


The association between regular physical exercise and improved sleep quality, including a reduction in the risk and severity of insomnia, is a well-documented phenomenon in scientific literature. A critique that emphasizes on the claim that exercising twice a week significantly reduces the risk of insomnia must consider several dimensions: physiological mechanisms, research evidence, exercise type and duration, and individual differences.



Physiological Mechanisms


Physical exercise has several physiological effects that could explain its positive impact on sleep patterns. Firstly, it can help regulate the body's circadian rhythm, enhancing the natural sleep-wake cycle. Exercise also stimulates the release of endorphins, which can alleviate some forms of pain and stress, potentially reducing factors that can contribute to insomnia. Moreover, it has been suggested that exercise can decrease levels of the body's stress hormones, such as adrenaline and cortisol, which could directly improve sleep quality. However, the intricate balance between physical activity and these physiological processes is not fully understood, and the optimal conditions (type, intensity, and timing of exercise) for these benefits are still under investigation.



Research Evidence


An abundance of research supports the idea that regular exercise contributes to better sleep patterns. However, the prescription of "twice a week" as a specific frequency that significantly reduces the risk of insomnia requires careful examination. Most studies in this area use diverse methodologies, participant profiles, exercise routines, and measurement of outcomes, which can lead to variations in conclusions. While there is substantial evidence that regular exercise (on most days of the week) is beneficial for sleep, the assertion that exercising specifically twice a week is significantly beneficial may not be strongly supported in every context. The variability in individual responses to exercise regimens should also be taken into account when interpreting these findings.



Exercise Type and Duration


This examination would be incomplete without considering the type and duration of exercise involved. Not all forms of physical activity have the same impact on sleep quality. Aerobic exercises like running, cycling, and swimming are frequently associated with improvements in sleep, but the effects of resistance training, yoga, and other forms of exercise are also noteworthy. The duration and intensity of the exercise session can further modulate its effects on sleep. While moderate-intensity aerobic exercise for 150 minutes a week is widely recommended for general health, the specific prescription for preventing or alleviating insomnia may differ. The claim regarding exercising twice a week significantly reducing insomnia risk does not encompass these nuances.



Individual Differences


Finally, any examination must acknowledge the role of individual differences. Factors such as age, health status, baseline physical activity levels, and even genetic predispositions can influence how exercise affects sleep. For some, twice-weekly exercise may indeed be a significant improvement from a sedentary lifestyle and thus yield noticeable benefits for sleep quality. For others, particularly those who are already quite active, an increase to twice-weekly exercise may not have the same impact.




In summarizing, while a broad body of research underscores the benefits of regular exercise for enhancing sleep quality and reducing the risk of insomnia, the specific claim that exercising twice a week is significantly effective warrants a nuanced critique. The body of evidence supports the general notion of physical activity improving sleep but pinning down the efficacy to a twice-weekly schedule oversimplifies the complex interplay of exercise type, intensity, duration, and individual physiological responses. However, that said, the study mentioned below examines the effect of twice weekly exercise on almost 4,400 indiviudals aged 39-67 year, of whom 25% were physically active.


Future research should aim to further elucidate the optimal exercise prescriptions for specific sleep-related outcomes, taking into account the diverse needs and capacities of the population.


Your health is your most valuable asset, and we are here to support you every step of the way. In light of the study’s conclusions, the key take away is that engaging in even minimal exercise is preferable to none at all, providing substantial benefits to both your mental and physical well-being.


Exercising twice a week slashes risk of insomnia


People who maintain an active lifestyle have been found to be 42 per cent less likely to report difficulties falling asleep, and also tend to clock up at least six hours of sleep each night.

A study looked at the exercise habits of 4,399 adults from nine European countries including the UK, aged between 39 and 67, who were followed for ten years. One in four participants were classed as “physically active”, meaning they consistently did exercise such as going for a jog or a swim at least twice a week.

At the end of the ten-year study period, all the participants were assessed for factors indicating insomnia, including daytime sleepiness and how many hours they slept each night.

This physically active group were significantly less likely to suffer from insomnia, according to the research published in the journal BMJ Open. Compared with those who did not exercise, they were 42 per cent less likely to find it difficult to fall asleep, and 22 per cent less likely to have any symptom of insomnia including waking up during the night or daytime sleepiness.


The active participants were also 55 per cent more likely to get the recommended six to nine hours sleep a night compared with those who did not exercise. Previous studies have shown that exercising helps improve poor sleep, but the new study is one of the first to show how maintaining the habit in the long term is vital to preventing insomnia from taking hold.

Those who took up exercise during the ten-year study period were also less likely to have insomnia, but still at greater risk than those who had regularly exercised for at least a decade.

The research was led by a team at Reykjavik University in Iceland, and used data from the European Community Respiratory Health Survey. The authors said: “This study has a long follow-up period (ten years) and indicates strongly that consistency in physical activity might be an important factor in optimising sleep duration and reducing the symptoms of insomnia. Those who are physically active in general are also more likely to engage in a healthier lifestyle, which can likewise have an effect on sleep.”

The study suggests physical activity is an important factor in helping people sleep properly


Another study published on Tuesday found that periods of poor sleep can leave you feeling up to ten years older. Even just two nights of restricted or disturbed sleep can make you feel between four and five years older compared with someone who had two nights of high-quality rest.

Researchers at the Karolinska Institute in Sweden took 429 participants and asked them to assess their own “self-perceived age”, asking whether they felt older or younger than their years, and asked how this feeling was affected by the quality of their sleep over the previous month.

They then enrolled 182 people in a study where their sleep was restricted to see if it affected how old they felt.

After two nights with only four hours of sleep, people felt an average of 4.4 years older compared to those who slept for up to nine hours.

Those who were well-rested, scoring a one on the Karolinska Sleepiness Scale, who then experienced a period of poor sleep, moving to a score of nine on the sleepiness scale, ended up feeling an entire decade older.

The study, published in the journal Proceedings of the Royal Society B: Biological Sciences, concluded: “These findings provide compelling support for insufficient sleep and sleepiness to exert a substantial influence on how old we feel, and that safeguarding sleep is likely a key factor in feeling young.”

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