sleep

London calling…

What about you, are you a dreamer?

Nikita khandelwal

Nikita Khandelwal

In a previous post, I told you that the new and unprecedented lockdown period had led to three major types of sleep disruption. Consequently, some people told me about sleep disruption induced by a high level of anxiety related to the pandemic. These people admitted to more frequent, sometimes strange and at times even worrying, vivid dreams. Let me tell you about Laura’s dream, which recurred throughout the lockdown. In her dream, she is a passenger on a plane about to take off at night. Safely secured in her seat, the plane picks up speed at a normal rate and takes off. Suddenly, the pilot announces loudly through the loud-speakers that a technical problem has occurred on the plane, forcing it to land in emergency. Laura clutches her seat belt as if her life depended on it. The plane lands in a crash, shaking the passengers in every direction. She takes a look out of the window, and notices that the plane is speeding relentlessly through the streets of London and on the Thames, while the leader of The Clash starts singing London Calling… The world of dreams still has a lot of mysteries to offer, for Laura and for everybody else. This is indeed a particularly intense subject of research which enables us to learn more every day about the role of dreams. Thus, bad dreams such as Laura’s lockdown one are very typical in stressful situations, and validate one of the recent theories about the functions of dreaming: to virtually simulate a threat, in order to better face it during the day. Laura simulates a virtual lockdown - attached on the plane - to better face it during the day, all while trying to escape from this situation by projecting herself towards a future escape in a capital city. In other terms, dreams mainly have the function of emotional regulation. But that’s not it. Some high-level athletes I accompany shared with me their concern about dreaming less than during a normal training period. For a high-level athlete training between 30 to 35 hours per week, the stark reduction in diurnal activity during the lockdown may indeed have been problematic, and indirectly spilled over onto their ability to dream. The quantity of movement throughout the day influences the quality of your sleep. There is still a lot to discover but the vestibular system of the inner ear, which is particularly sensitive to gravitational stimulation, may have an influence on your sleep. It informs the brain about the daily amount of activity, quite like an actimeter which records your number of steps throughout the day. Indirectly, this could contribute to a higher or lesser amount of dreams. That way, astronauts in space have a reduction in rapid eye movement sleep duration. This sleep stage produces the most dreams, it is reduced in space due to the absence of terrestrial gravity. Thus, your night’s dreams are a valuable piece of information for the day ahead. And the quality of your day favours a tendency to dream. What if, starting tomorrow morning, you took the time to think about your dreams and why not even write them down in a dedicated notebook?   

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

What is a good night’s sleep? Like a good meal: it depends…

What do you consider to be a good night’s sleep?

Daria shevtsova

Daria Shevtsova

What if a good night’s sleep for you were to fall asleep easily and remain in Morpheus’ arms until the gentle sound of your alarm-clock goes off? Or rather dream vividly and when you wake up get the answer to the question that has been gnawing at you for such a long time, in the easiest possible way? Or even wake up in the early morning, realise with pleasure that you still have the freedom of lying in bed, and put yourself in snooze mode for another few hours? To this easy-looking question, there are a multitude of possible answers. Answers that might be as diverse and different to the following one: for you, what is a good meal? I suggest we apply the analogy of a good night’s sleep to a good meal. Let’s consider for a moment the experience of a nice dinner. Surely, elements such as the quantity and quality of food contribute to feeling satisfied. If some of you enjoy an all-you-can-eat buffet, others focus more on the quality of the products. The sleep quantity (number of hours of sleep per night) as well as its quality also contribute to feeling satisfied by a good night’s sleep. But that is not everything. To enjoy a nice dinner, the presentation of the dish, the price or even the atmosphere are other elements to take into consideration. If some of you are looking for a restaurant dinner, others would prefer a home-cooked meal… In the same way, our sleeping environment contributes to good sleep quality. Finally, feeling satisfied by a night’s sleep cannot be reduced to the quantity and quality of your sleep. A good night’s sleep is the sum of multiple components: 1) its subjective quality; 2) sleep onset latency or the time required to fall asleep; 3) how long it lasts; 4) the efficiency of your sleep; 5) possible disruptions during the night; 6) possible medication intake; 7) difficulties encountered during wake time. Thanks to this questionnaire, you will be able to seriously assess your sleep and understand where you’re at. And then follow up on your progress, month after month. Defining a good night’s sleep is pretty complex, and the retained definition varies from person to person. These seven components are measured by a questionnaire called the “Pittsburgh Sleep Quality Index” or PSQI which evaluates your sleeping patterns throughout the last month. In the meantime, for those of you who wish to control their sleep, a multitude of solutions and strategies exist which can help improve the quality of your sleep. And to stretch the analogy, the need or the act of napping does not say much about your overall satisfaction in relation to your nocturnal sleep, just as snacking after a meal does not necessarily mean that you did not enjoy it!                        

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

Napping: sleepiness or sleepability?

What about you, are you a napping enthusiast?

Mateusz dach

Mateusz Dach

We are progressively coming out of lockdown. This unprecedented period will have upset a good deal of our habits. Let’s take the example of Axel, a young executive who found himself working from home overnight. But can we truly speak of remote working to qualify a similar work load which needs to be done in a productive and efficient time which is very condensed and requires to be carried out during two toddlers’ napping time? Indeed, Axel hasn’t had the time to nap since the beginning of the lockdown. Just after a mentally-exhausting morning, followed by a very quick lunch, the start of the kids’ napping time kicks off a period of work which he hopes to be as productive as possible. We can identify three types of naps, depending on the objective: preventing or prevailing against the diurnal sleepiness? Have you ever experienced that feeling of drowsiness that you usually come at the beginning of the afternoon and which can be a symptom of sleep debt?

A preventive nap is taken in anticipation of a future sleep restriction;

A compensatory nap is taken after a sleep restriction;

The “appetitive” nap is taken for comfort or pleasure. A study even showed that an “appetitive” nap, with an immediate sleep initiation, was associated to better nocturnal sleep quality, and was not linked to diurnal sleepiness. So, napping: sleepiness or sleepability? Another study which was carried out among elite athletes showed that they went to sleep faster compared to active subjects. This was the case for the first - which fits the challenge of sleeping in a new sleeping environment - and the second nap of the study. These results remained valid in mathematical models which controlled sleepiness and the amount of sleep gathered prior to the experiment. In other terms, the ability to fall asleep at one’s pleasure could be linked to a certain training, and not only to previous sleep restriction-induced pressure. As children are gradually allowed back at the nursery, Alex will make the most of this afternoon to give the “appetitive” nap a shot! Contrary to pre-conceived ideas, this could even help him enjoy a better night’s sleep tonight!                 

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

Meditation: an ally for your sleep during lockdown

What about you, are you meditating during the lockdown?

Spencer selover

I told you in a recent post, that several people had been experiencing sleep disruption since the lockdown began. This unprecedented lockdown situation has actually led to three major types of sleep disruption, and sleep can notably be disrupted by a high level of anxiety linked to the pandemic. This adds to the problem considering a good quality of sleep can protect you from viruses. The studies held in China on the effects of the lockdown have unsurprisingly shown acute levels of anxiety, difficult emotional management and several cases of post-traumatic stress disorder (PTSD) when the lockdown exceeds a period of 10 days. The lockdown may lead to a type of boredom, a frenetic desire to keep up with the news, while isolation may hinder the sharing and expression of anxiety-inducing thoughts. A short daily session of mindfulness - a branch of meditation - may be a strategy to nurture your confined sleep! Mindfulness can be defined as total awareness, without judgement, rooted in the present; it has already shown its benefits to treat certain sleep pathologies. What about during this unprecedented period of lockdown? A study conducted in the Chinese province of Wuhan, which was the first to be hit by the virus, offered participants a 10-min meditation session every morning on a smartphone (lockdown rules!), during a period of 10 days. The control group was offered a 10-min session of relaxation. The meditative session invited participants to focus on the present moment, be aware of what’s happening at every second, and to accept it. First positive result: the meditators noticed a lower level of daily anxiety. The sleep of those who had only taken part in the relaxation session was impacted throughout the follow-up period: on average, they lost 40 minutes of sleep per every 1000 cases of Covid-19 announced by the media. The meditators’ sleep duration remained unchanged throughout the same period. So why don’t you give it a go as from tomorrow? A meditation session in the morning, maximum 30 minutes of exposure to the news per day, and avoid checking it right before bedtime. The current lockdown situation can also serve as a good opportunity to take a step back and focus on your inner self…

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

A clever approach to screens will preserve your sleep!

What about your relationship to screens?

Fauxels 3

Fauxels 3

An ordinary and hyperconnected work meeting. Different protagonists each set up their computers, smartphones and tablets. The meeting will last one hour and half during which a number of them will hastily check each of their devices… Young adults are obviously also concerned. According to a recent survey, 90% of them browse on social media (Facebook, Instagram, Twitter, etc.) during the two hours leading up to bedtime, and 59% of them have their phones on in the bedroom during the night. Whoever says phone on says nighttime texting with a night-owl friend and fostering of the “connected night-owl club”! In addition to the detrimental effect of an excessive use of new tech throughout the day on sleep (Thomée et al., 2007), exposing oneself to screens before going to bed is also counter-productive. Such an exposure will increase our level of vigilance, partly due to a blue-light induced reduction in melatonin secretion, and the engaging and stimulating content of this media. According to Arora et al. (2014), complex cognitive processes (decision-making, problem solving, memorisation) happen when using these forms of media. This might lead to a difficulty to switch off the brain and let go when initiating sleep. You have to know that unhealthy consequences will depend on the chosen format. Thus, obsessively checking and posting comments on Facebook before going to bed will result on average in one hour less of sleep per night! Watching TV before bedtime will result in twenty minutes less of sleep whereas listening to music will make it hard to fall asleep (Arora et al., 2014). Finally, unlimited access to artificial light and the possibility of creating permanent artificially-lit environments are crucial factors in the reduction of sleep quantity among industrialised societies. According to philosopher Michel Serres, with the birth of new technologies, a new kind of human was born: he calls him “Little Thumb”, referring to the maestria he has to send texts with his thumbs. His theory invites us to reconcile modern and old. It seems difficult today to advocate in favour of the suppression of new technologies, which are everywhere, along with permanent digital logout in order to preserve sleep. A clever use of new technologies is still possible. It is a question of taking back control over our relationship with technology.                               

Use with caution! James Williams, a former Google employee, who quit to become a philosopher said: “On the short term, technology distracts us from tasks we have to do. On the long term, it may distract us from the life we want to lead… Technology favours our impetus and not our intentions”.

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

Myths and beliefs surrounding sleep

What about your beliefs surrounding sleep?

Isabella mariana

Pixabay 2

In terms of health, many beliefs are transmitted in spite of low levels of scientific evidence. They can either promote or refrain from adopting healthy habits. Sleep does not escape this rule and several myths are hard to beat! It is important to identify these myths - which are shared by relatives, the media, press, forums and the Internet - and assess their scientific level of evidence. In a recent study (Robbins et al., 2019), a Delphi procedure was implemented with 11 experts in order to assess the falsehood and importance of some myths surrounding sleep on public health. Authors finally established a list of 20 myths classified into six categories: sleep quantity; sleep timing; nightly habits; daily habits and their impact on sleep; behaviour prior to bedtime; brain activity throughout the night. Among the identified myths, we can find that of “short sleeper” which stipulates that some adults need only 5 or less hours of sleep in order to be fit. Another one refers to a recurring question: if I don’t manage to sleep, should I stay in bed or get up? Another myth refers to snoring: apart from the nuisance it causes for the partner, in most cases it wrongly appears to be without danger for the sleeper. Better identifying and understanding myths and beliefs surrounding sleep is a first step towards: 1) promoting beliefs based on scientific evidence; and (2) proposing educational interventions on sleep.

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

Evening exercise and sleep

Evening work-out or a good night’s sleep: do we really have to choose? 

Pixabay

Pixabay

Monday night, 10:30pm in Paris. As one of January’s cold snaps hits me, I walk home as briskly as possible. When turning a corner, I am attracted by a particularly bright window. As I get closer, a loud and catchy song becomes clearer to me. A gym! Behind the window, a dozen athletes are trying to keep up with the coach’s pace. A barely visible drop of sweat is running down his forehead, and he has the decency at the end of the class not to tell his students that it is his seventh class of the day… This ordinary urban event is the opportunity to answer one of the most frequently asked questions during my interventions: “does evening exercise disrupt my sleep?”.

Medical doctors and public opinion generally tend to discourage intense evening exercise, during the period leading to bedtime. Such an exercise would impair the quality of sleep during the following night. Today, there is very little proof in scientific literature to support the evening sofa option rather than outdoor running or on a treadmill in the gym. In 1976, Browman and Tepas certainly showed an increase in sleep onset latency - or the time required to fall asleep - following late-night exercise. The significant increase in sleep onset latency was of 6 minutes after a 45-min cycling session performed only five minutes prior to bedtime! As fast as you may be to shower, go home and enjoy a little snack, we can bet that the recovery period between the end of your session and bedtime is longer… Several studies have shown the lack of effect or even positive changes on sleep from an evening exercise. For example, Buman et al. (2014) have shown, in a large cohort of 1 000 adults, that fans of evening exercise - performed less than 4 hours before bedtime - display a similar sleep or a better sleep on exercising days compared to resting days. What’s more, a meta-analysis gathering the results of almost 3 000 adults concluded that exercising less than 3 hours prior to bedtime is beneficial for sleep, i.e. less wake after sleep onset and less light sleep     throughout the night (Kredlow et al., 2015). And what about exercise intensity? Performing an exercise subjectively perceived as difficult one and a half hours before bedtime is associated with better sleep quality and a reduction in sleep onset latency (Brand et al., 2014).

Our core body temperature follows a circadian rhythm, very close to 24 hours. It is at its lowest around 3:00 or 4:00am and increases progressively before peaking between 6:00 and 8:00pm. Between these hours, is the ideal window to outdo your personal record! Sleep initiation is then linked to a decrease of your core temperature (approximately 0.5 to 1°C) and deep sleep is made more possible during the first part of the night if our core body temperature is reduced. The general advice of not exercising in the evening is mainly based on the assumption that evening exercise, especially if intensely performed, will increase core body temperature and threaten sleep quality. Reality is much more complex. To see clearer, we studied the influence of a high-intensity trail undergone in the lab at 9:00pm on well-trained runners’ sleep assessed by polysomnography (maximal aerobic speed superior to 18 km/h and VO2max of 70mL/min/kg). Results showed a slight change in sleep architecture during the night after exercising compared to the control condition. Core body temperature and heart rate were significantly increased throughout the first part of the night compared to the control condition. Another article which was published at the same time (Thomas et al., 2019) showed that an intermittent running exercise (6 sets of 5 minutes at 90% VO2peak; and 5 minutes recovery) at 6:00pm increased total sleep quantity during the subsequent night, even though an increase in heart rate was also observed.

It seems that evening exercising and a good night’s sleep are compatible! Regular physical activity paves the way to good sleep and long-term health. In order to maximise your chances, here is my list of strategies to favour your sleep after exercising in the evening:

1. Limit light exposition, especially to screens, and possibly wear tinted glasses.

2. Choose a milky beverage over water to ensure rehydration

3. Eat a high glycemic-index snack

4. Drink tart cheery juice and food rich in tryptophan (e.g. turkey, pumpkin seeds)

5. Set up an adequate sleeping environment: cool (18 to 19°C), peaceful and dark

6. Try out breathing exercises, which we will discuss next time

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

A poisoned gift

The excessive use of new technologies is detrimental to our sleep

Ivan Oboleninov

Ivan Oboleninov, Pexels

Axel has been having trouble sleeping for the past five years, after starting a new job that he was very much looking forward to. A promotion that opened up a lot of doors, but closed the doors on a good night’s sleep. His fiancé, who was worried about the state of his health, bought him one of the numerous sleep trackers available on the market for Christmas. Since then, he has been constantly wearing it on his arm but has been unable to fall into Morpheus’ arms. Axel is not the only one, around 10% of the population uses one these tracking devices whereas half of us would consider purchasing one sooner or later. Recently, a new word has sprung up to qualify people who are obsessed with controlling their sleep: orthosomnia (“the right amount of sleep”). The first thing these people do when getting up is to check the night report granted by the app connected to the device. They anticipate that it is going to be a hard day when the summary displays less than 8 hours of sleep. Some of them even check their phone to live track their night’s sleep, every time they wake up. However, two methods are currently scientifically proven and used to track sleeping patterns: actimetry and polysomnography. If actimetry records with precision our movements during the night, only polysomnography can record electric cerebral activity. Actimetry, along with most of the trackers available on the market, is not able in any way to define the different stages of sleep (i.e. light sleep, deep sleep and rapid eye movement sleep). Only polysomnography is able to. Several scientific studies have indeed shown that available trackers are incapable of precisely ascertaining the different stages of sleep, as well as waking time throughout the night. What’s more, a lack of transparency in the algorithms makes it difficult to conduct any kind of validation study. So, there is an urgency for Axel and hyper connected people to take back control over their sleep and to leave sleep trackers and all of their data in their right place. If you are using such a device, please share your experience with us by clicking here.

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.

A poisoned gift

The excessive use of new technologies is detrimental to our sleep

Ivan Oboleninov

Ivan Oboleninov, Pexels

Axel has been having trouble sleeping for the past five years, after starting a new job that he was very much looking forward to. A promotion that opened up a lot of doors, but closed the doors on a good night’s sleep. His fiancé, who was worried about the state of his health, bought him one of the numerous sleep trackers available on the market for Christmas. Since then, he has been constantly wearing it on his arm but has been unable to fall into Morpheus’ arms. Axel is not the only one, around 10% of the population uses one these tracking devices whereas half of us would consider purchasing one sooner or later. Recently, a new word has sprung up to qualify people who are obsessed with controlling their sleep: orthosomnia (“the right amount of sleep”). The first thing these people do when getting up is to check the night report granted by the app connected to the device. They anticipate that it is going to be a hard day when the summary displays less than 8 hours of sleep. Some of them even check their phone to live track their night’s sleep, every time they wake up. However, two methods are currently scientifically proven and used to track sleeping patterns: actimetry and polysomnography. If actimetry records with precision our movements during the night, only polysomnography can record electric cerebral activity. Actimetry, along with most of the trackers available on the market, is not able in any way to define the different stages of sleep (i.e. light sleep, deep sleep and rapid eye movement sleep). Only polysomnography is able to. Several scientific studies have indeed shown that available trackers are incapable of precisely ascertaining the different stages of sleep, as well as waking time throughout the night. What’s more, a lack of transparency in the algorithms makes it difficult to conduct any kind of validation study. So, there is an urgency for Axel and hyper connected people to take back control over their sleep and to leave sleep trackers and all of their data in their right place. If you are using such a device, please share your experience with us by clicking here.

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.                

Sleep in Western countries

And what about you, do you get enough sleep?

Acharaporn kamornboonyarushs

Here we are in 2020 and it’s already a new decade. New Year’s night was a very short, festive and maybe even sleepless one for some of you. And what if taking care of your sleep was your new year’s resolution? Surveys led by public health authorities in Western countries are clear. A large proportion of us doesn’t get enough sleep. French people, for example, sleep on average 6 hours and 42 minutes per 24-hour cycle. The average sleep duration has reached the critical level of less than 7 hours! This is a public health issue. An organization of sleep experts recently penned an article with the provocative title: “Our lack of sleep is killing us”. Approximately 30% of the population sleeps less than 7 hours a night. During one of your next nightly awakenings, just be curious and look out of your window onto the sleeping city. You will then be able to count the lit-up windows, rather than sheep, and will realize that you are far from being the only one… However, sleep plays a crucial part in physical (thanks to deep sleep) and psychological recovery (the role of rapid eye movement REM sleep). The recommended sleep duration for an adult between the ages of 18 and 65 is anywhere between 7 to 9 hours. Rest assured: solutions exist! First of all, sleep must be reinserted into a general context of sleep-wake rhythms. The quality of your night will depend on the quality of your day. Regular physical activity and good emotional management are already strong allies. Moreover, similarly to a switch, strategies exist in order to easily switch from wake to sleep mode throughout the evening. And then swiftly from sleep to wake mode in the early hours of the morning. Light therapies, nutrition, bedding, cooling down, sleep extension, etc. are examples of some of these strategies. Several scientific studies have revealed the superiority of cognitive behavioural therapies over sleeping pills, without the potential side effects linked to the intake of medication. There is an urge to take action and care for your sleep! We will accompany you in this ever-so-crucial process.

Mathieu Nedelec, sport scientist in charge of research projects on sleep and recovery. I teach best practices to improve sleep and performance. I will read your answers carefully and let you know when my next posts will be published.