Sorting through a few of the biggest myths around sleep and circadian health with a man who really knows
There’s a lot of well-established advice on the dos and don’ts of sleep, but how much of it is true? And instead of being helpful, could it actually be fueling the real enemy of better sleep – our own sleep anxiety? We asked Russell Foster, one of the world’s leading experts on sleep and circadian health, Professor of Circadian Neuroscience at Oxford University, and an ainslie + ainslie brand advisor, to clear some things up, once and for all.
1. We all need eight hours a night.
“Society has become fixated on this mythical number to such an extent that our reaction to not hitting it becomes the problem. In fact, it’s just an average and we all have our individual requirements that range between 6 and 10 hours and vary depending on age and individual needs,” says Foster. “We all have different sleep needs, and like shoe size – one size does not fit all.”
How can you tell if you aren’t getting the sleep you need? A few tell-tale signs, says Foster, are feeling groggy when you wake, that you aren’t performing at your peak during the day or if you find yourself behaving irritably, impulsively or without empathy in fairly ordinary, everyday situations.
2. Waking up in the night is a sign of being a poor sleeper.
“Similarly, we have been led to believe that sleep needs to be in one block (monophasic) and that waking up in the night is problematic. It’s not,” says Foster. “Studies show that sleep in two blocks (biphasic) or more (polyphasic) is very common. If you do wake up, stay calm, avoid getting stressed and reaching for the phone, keep the lights low, you may want to leave the bed and do something relaxing, and when sleepy return to bed. The key thing is not to lie there getting frustrated and anxious. Many colleagues of mine will listen to a relaxing story on catch-up radio and are back asleep in no time at all.”
“We all have different sleep needs, and like shoe size – one size does not fit all.”
3. Caffeine in the afternoon leads to a bad night’s sleep.
“What caffeine does is block the receptors in the brain which detect adenosine, which builds up the longer we’ve been awake - it’s called sleep pressure and so when we take a cup of coffee, the brain is less able to detect how sleepy it is,” says Foster.
However, instead of having a fixed effect, it actually varies significantly from person to person.
“Some people are exquisitely sensitive and a coffee in mid-afternoon can delay sleep onset many hours later. Others can drink several espressos just before bed and it won’t affect them,” he adds.
Again, Foster suggests finding your own threshold, but suggests no caffeine after 2 or 3pm as a rule of thumb.
4. We should all get light in our eyes first thing in the morning.
Most of us, yes, but not all. It depends on your chronotype. “About 90% of us would benefit from getting out into daylight first thing in the morning as a way to set or “entrain” the circadian clock and sleep/wake cycle,” says Foster. “Morning light advances the clock and counteracts the drift to a later time seen in mid- to late-chronotypes (owls and doves). However, the remaining 10% of us who are genuine larks (early chronotypes) and wake up early every day would benefit from doing the opposite – going outside at dusk in order to delay the clock.”
5. Daily naps can be useful for banking sleep.
“An occasional nap of less than 30 minutes is probably fine, but if you become dependent on them to get through the day, that’s when I get a little uneasy,” says Foster. If they become longer and closer to bedtime, that’s when they disturb our natural rhythms.
“If they’re longer than 30 minutes you can fall in to a deeper sleep and so recovery from that deeper sleep can leave you groggy,” he explains. “If they’re closer to bedtime, that can also be a problem because it pushes back the sleep pressure and makes it harder to get to sleep that night.”
6. An evening drink is a good way to get to sleep.
“A drink before you go to bed can be relaxing but if you’re using alcohol to get to sleep, you’re not getting sleep, you’re getting sedation,” says Foster. “It can actually be harmful to some important things going on in the brain whilst you sleep, like memory formation and the processing of information to come up with novel solutions to complex ideas. So don’t use alcohol as a sedative, it’s a really bad idea.”
7. Blue light before bed will affect sleep quality.
This one has quickly become an established ‘fact’ but scientifically the light itself isn’t likely to be a problem. “The sort of light and levels of light you get from computer screens, tablets or phones isn’t really bright enough to have much of an effect so I don’t think we should be too worried about blue light,” he explains. “Clearly if the light is bright, whatever colour or wavelength it is, it can increase alertness and delay sleep, but there’s no real evidence that light from most devices will impact our sleep or circadian rhythms.”
A lot of us have grown up with the mindset that sleep is something that just happens to us, but our actions during the day can play a huge role in our sleep quality, starting from the moment we wake up.
By taking the anxiety out of sleep through understanding our body clock better, Foster suggests we can use this knowledge to get the sleep that each of us needs.
ainslie + ainslie NIGHT POWDER is designed to work with the body’s natural circadian rhythms to promote deep, restorative sleep and cellular recovery.
