We spoke to Dr Nicola Barclay, a lecturer in Sleep Medicine, to find out how changing our sleep patterns could have a positive impact on our training
We don’t know about you, but our sleep went a little crazy over the first lockdown – we were either sleeping too much or too little, but never quite the right amount. With a second lockdown underway, we want to make sure we get this bit right. Why? Because as women, we know how important sleep can be: a bad night’s sleep can affect everything the next day. Our work, our relationships with others, our nutrition, and our running. Conversely a good night’s sleep can have a positive impact on all those things, but sometimes getting that good night’s sleep is easier said than done. Juggling hormones, family, work and countless other demands means that our sleep health is sometimes the last thing on our minds, and many of us are surviving on far less than we actually need.
But how much do we need? And how can we adjust our sleep patterns to improve our training and the rest of our lives? We spoke to sleep scientist Dr Nicola Barclay who works in partnership with sleep and comfort brand Mammoth to find out how sleep affects us as women and as runners, and how our sleep can affect us, as well as to find out what we can do to get the best sleep we possibly can do. Spoiler: we have a sneaking suspicion this may involve caffeine…
What factors can affect the quality of our sleep?
“Almost every part of our waking day has an impact on our sleep, from how regular our daily routine is, including the timing of activities and meals; to how much light we have exposed ourselves to and whether we have partaken in any exercise. The sleeping environment also affects our sleep quality, being too hot or too cold, being uncomfortable, external noises. But in addition to these more environmental factors, our sleep is affected by our moods, by stresses in our lives, our responsibilities and relationships.”
What can genetically predispose us to sleep badly?
“A lot of my research has used twin studies to determine the heritability of insomnia and sleep quality. We know that sleep quality is around 40% heritable, which means that of all the differences in the sleep quality of the population, 40% of that variability is explained by differences in our genes (i.e. there are genes that predict whether someone is a good or poor sleeper). This point is also exemplified by family studies which show that insomnia runs in families. There has been a lot of work to identify the genes involved in sleep quality and insomnia, but a lot of this research is inconclusive. It appears that there are multiple genes that work in concert to bring about poor sleep, rather than there being one gene involved. That said, the environment plays a larger part in dictating our sleep quality (explaining the remaining 60%). It has also been hypothesised that an individual with a genetic predisposition to poor sleep may only exhibit poor sleep in the face of some environmental stressor. That is, an environmental stressor acts as a trigger for an episode of poor sleep. This is an important point, as it means that we are not a slave to our genes, that even those with a genetic predisposition to poor sleep are not destined to experience poor sleep. The environment is modifiable, so to some extent we have the power to override what is laid out in our genetic makeup!
“That said, there are numerous sleep disorders, other than poor sleep quality or insomnia. Sleep disorders can be categorised into insomnias, sleep-related breathing disorders, sleep-related movement disorders, circadian rhythm disorders (relating to the timing of sleep), hypersomnias (sleeping too much, including idiopathic hypersomnia and narcolepsy), and parasomnias (“things that go bump in the night”, such as sleepwalking, amongst others). Correctly identifying the sleep symptoms, the timing of sleep as well as disturbances, and the presence of daytime sleepiness are key to determining the best method of treatment. Treatments for these different sleep disorders are highly specialised and specific, and so correct diagnosis is essential.”
How does our mental health affect our sleep?
“There are bidirectional links between our mental health and our sleep, particularly anxiety and depression. What this means is that our sleep impacts our mood, and our mood impacts our sleep. Feeling anxious, particularly about getting to sleep, makes sleep more elusive. Trying too hard to get to sleep makes getting to sleep much harder. Feeling tired the next day can then increase anxiety and perpetuate a negative cycle of disturbed sleep. Worries about our daily lives also make it difficult to sleep soundly. But sleep itself is essential for the regulation of our emotions – it is known that REM sleep pays an important role in emotional regulation, so a poor night of sleep is likely to exacerbate difficulties with our emotional control and reactions to stress. The reasons behind these associations lies in the fact that the same brain chemicals involved in sleep are also involved in mood. For these reasons, it is important to approach difficulties sleeping alongside a management of our mental health, as these factors are intricately intertwined.”
What specifically affects women when it comes to their sleeping patterns?
“A wealth of data highlights that women are more likely than men to experience poor sleep and insomnia. There are numerous reasons for this sex difference in sleep, including genetic, physiological and social factors. Firstly, there is some research to suggest that females may have a greater genetic component impacting sleep. Secondly, women experience a change in the levels of oestrogen and progesterone during different phases of the menstrual cycle, as well as during peri-menopause, the menopause and post-menopause, and these can make it difficult to get to sleep and stay asleep. Finally, women are quite often the primary caregiver of children in the family, particularly when children are very young. Whilst this isn’t always the case, it is often that women are taking on multiple roles relating to their home, families and careers that time to relax and sleep becomes a luxury not often afforded.”
What about peri and menopausal women: sleep disruption is a common symptom, what can women going through the menopause do to combat that?
“The perimenopause and menopause are known to disrupt sleep, this is primarily for two reasons, firstly, the drop in production of progesterone and oestrogen that occurs during the perimenopause brings with it a host of physiological changes, including changes in energy, sex drive, mood, cognition and sleep. Importantly, oestrogen is involved in the chain of events that produce serotonin and melatonin –neurochemicals that have important roles in sleep onset and maintenance. But these neurochemicals are also involved in the regulation of our mood, and so we can see how the menopause may impact both our sleep and mental health due to the hormonal changes taking place. Secondly, sleep during the peri- and menopause is disrupted by ‘hot flashes’ and night sweats. Our bodies naturally need to be cool to initiate sleep, and the rise in body temperature that is common in menopausal women can make sleep challenging. We should do all we can to make the bedroom and bed cooler, wearing loose fitting pyjamas (and going bare if you dare!), and using cool cotton sheets. Simple sleep hygiene tips such as those outlined above can optimise your chances of a good night’s sleep. Individuals experiencing chronic difficulties getting to sleep or staying asleep should consult their GP for a more thorough assessment, as there may be some underlying sleep disorder affecting sleep that warrants more specific treatment (such as cognitive behavioural therapy for insomnia).”
What can everyone do to try and get the best night’s sleep possible?
“Whilst some sleep disorders require specific treatment, for individuals experiencing a bout of poor sleep there are things we can do to optimise the conditions for sleep.
– Keep a regular routine. Identify when your optimum ‘sleep onset zone’ is and stick to it. Our brains and bodies need routine, so ensure that you wake up at the same time each day, yes even at weekends, to ensure that your circadian rhythm is well entrained.
– Reduce caffeine intake: Caffeine keeps us alert and awake by influencing neurochemicals which interfere with the homeostatic sleep drive. Having too much caffeine reduces your sleep drive, making it difficult to get to sleep and stay asleep. Caffeine has a long half-life, meaning that the time it takes for your body to metabolise it is around 5 hours. This means that if you have a double espresso around 5pm, you are likely to still have as much caffeine in your system at 10pm as having a single shot of espresso. Would you really have an espresso before going to bed?! I thought not.
– Reduce your alcohol intake: Alcohol also interferes with our sleep. Whilst a nightcap can help us get off to sleep, the sleep during the second half of the night is seriously disrupted. It becomes more fragmented, we are more likely to awaken to use the bathroom, and the amount of Rapid Eye Movement sleep (REM) we obtain is reduced. This sleep stage helps us regulate our emotions, so we are likely to not only feel tired after a night on the booze, but also more emotionally reactive the following day.
– Eat healthily: certain foods such as bananas, egg, poultry, tart cherries, contain or help our bodies to secrete melatonin, a hormone that makes us feel sleepy. Eating such foods in the hours leading up to bedtime could help you regulate your circadian rhythm and get to sleep at your optimum time.
– Reduce screen time: Melatonin, the hormone we just mentioned which can help you get off to sleep, is inhibited by light, particularly blue light. Electronic devices such as phones, tablets and computers emit a lot of blue light, and so evening screen time can seriously disrupt our circadian rhythm, pushing it later and later. Limit your screen time a couple of hours before bed or use a screen filter or ‘night mode’ if you really must use these devices in the twilight hours.
– Exercise, but at the right time: exercise during the day has been shown to boost slow wave sleep (SWS), the sleep stages that help you feel restored and replenished. Get outside to expose yourself to natural daylight to synchronise your circadian rhythm with the light-dark cycle and get some exercise to boost those slow waves. Though exercise in the couple of hours before bed may raise your body temperature to such an extent that it is difficult to get to sleep. Our body needs to be cool to get to sleep, so exercise earlier in the day.
– Have a hot bath before bed: This may sound counterintuitive given that our body needs to be cool in order to get to sleep, but having a hot bath means that when you hit the cold air when you get out of the bath stimulates your body’s natural cooling, and so your core body temperature reduces faster aiding your transition to slumber.”
Why do runners need to be attuned to their sleeping patterns?
“We all have a circadian ‘clock’ which controls our rhythms of wakefulness and alertness, as well as mood, cognition, and a whole host of physiological processes. This rhythm dictates our sleep-wake patterns, controlling when we awaken in the morning, our optimum times of peak performance, our sleepiness and when we go to bed at night. We are familiar with the terms ‘early morning lark’ and ‘night owl’ and these ‘chronotypes’ describe our tendencies to being a morning type or evening type. However, sleepiness and alertness follow predictable patterns of peaks and troughs throughout the 24-hour period. For example, a morning type (regardless of the sleep they obtained the night prior) will experience a rise in alertness, mood, and cognition, being at their peak performance in the late morning, followed by a dip after lunch, a further rise late afternoon, and beginning to feel sleepy in the early evening. Evening-types on the other hand feel groggy in the morning, have a rise after lunch and are usually at their peak performance in the evening hours. These patterns of performance to some extent remain consistent even after sleep deprivation. So even though sleep deprivation does alter our performance, the extent of performance impairment really depends on an individual’s chronotype and the time of day the activity takes place. The take home message is that we all have different times of peak performance, and so in order to perform at our best, we should listen to our internal clock for cues as to our own individual optimum times.”
What specifically affects athletes’ sleep?
“Exercise is great for sleep. Regular exercise can make it easier to get to sleep and stay asleep – there is evidence that exercise increases slow wave sleep, the sleep stage that helps make us feel refreshed. Though we should be careful about the timing of exercise. Exercise too close to bedtime can increase body temperature and physiological arousal, making it difficult to settle to sleep. We should aim to reduce physical activity in the couple of hours leading up to bedtime. We should also become attuned to our chronotype and to identify times of the day that we reach our peak performance – these timings will differ for morning types and evening types. One of the essential functions of sleep is bodily repair and cellular restoration. Growth hormone is also secreted during slow wave sleep. As such, sleep is vital for keeping our brains and bodies in tip top condition. Not getting enough sleep may make athletes more prone to injury and take longer to recover than those who regularly get enough sleep.
Sleep duration exhibits vast interindividual variability (see comment below). Thus, it is not always useful to assume that everyone needs the same amount of sleep. If we regularly obtain our required amount of sleep, meeting our ‘sleep need’ every night, we are unlikely to see gains in our performance for going over and above our sleep need. In fact, there is some research to suggest that getting too much sleep is problematic for health. Reaching our sleep need, and not over-sleeping is key. However, if we are regularly not reaching our sleep need, or are sleeping inconsistently across the week, making up for lost sleep by having a long lie in at the weekend, we are likely to experience decrements in our cognitive and physical performance, as well as mood and well-being.”
I’m also interested in the amount of sleep we actually need: the idea that teenagers need more than we do as adults. Who needs how much sleep? And how much of that is individual?
“The amount of sleep we all need is very individual, and it does indeed change across the lifespan. The American Academy of Sleep Medicine recommends children aged 3-5 should get between 10-13 hours sleep per 24 hours, school-aged children between the ages of 6-12 years require between 9-12 hours of sleep per 24 hours, and teenagers aged 13-18 should get 8-10 hours per 24 hour period. As adults, it is recommended that we get between 7-9 hours sleep, but we must remember that sleep is very individual. There are some individuals who can happily and easily function at their optimum, on only 4 hours sleep (and there are some notable historical characters who famously got by on so little sleep), whilst others need much longer. 8 hours is the average for the normal population. Therefore, we shouldn’t become fixated on this golden number of 8 hours, as it might not be optimal for everyone. Our sleep duration appears to be genetically controlled. You can work out your optimum sleep duration by trial and error, changing your sleep opportunity using an alarm and seeing how you feel. When you have slept your required amount, you should wake feeling refreshed.
There are also individual differences in our tolerance to sleep deprivation and again there are some genetic factors that account for these. We must remember that one individual’s sleep need is not the same as someone else’s, and we should appreciate everyone’s individuality in sleep as much as we appreciate their individual personalities.”
Find out more about how you can improve your sleep health here.
Rested up? Time to work on your running mindset.