When we think about sleep, almost anyone will tell you that getting eight hours is ideal. However, how many people have you met who swear by only getting six? Or those who get 10 or even 11 each night?
Dr Alison Bentley, Restonic Sleep Specialist, cautions against the idea that only eight hours can be considered normal and in fact, healthy. Dr Alison Bentley has been seeing patients with bedtime problems for 30 years and helped to run the first diagnostic sleep laboratory in South Africa. She believes that there is some room for deviation from commonly cited “normal sleep” in terms of three main components: duration, timing and solidity.
“What is normal sleep?” asks Dr Alison Bentley, Restonic Sleep Specialist. “It’s not a strange question, really. But while books and Google insist that normal sleep is 7-8 hours long, in one go from 10pm to 6am, how many of us actually rest like that? I find that people whose rest differs from this ideal often believe they have a sleep disorder. However, that’s not necessarily the case.”
While on average, sleeping can lie between seven and eight hours, that’s not to say the norm is the only kind that’s healthy. There are people whose bedtimes are only five hours long. Dr Alison says that while a sleep disorder could be in the realm of possibility, that person could also just be a naturally short sleeper. “The difference lies in how they function during the day,” notes Dr Alison. “The naturally short sleeper copes well and doesn’t feel tired, while the person with insomnia feels tired and fatigued with a deficit in attention resulting in poor concentration and memory difficulties.”
The sweet spot
So how can you tell if you’re getting optimum zzz’s? Dr Alison says you need to pay attention to how you feel after waking, and during the day. “The most important thing is that you need to feel that you have had enough when you wake up – that you are not fatigued or tired during the day,” she says. “Being able to concentrate and focus during the day on important tasks is also an important measure of enough rest. Good daytime function is a better measure of sleep rather than the right numbers at night.”
Timing your zzz’s
While many people catch naps between 10pm and 6am, there is variation in terms of timing. “Some people are like larks and go to bed early and wake early – feeling refreshed and ready to go to the gym at 5am,” says Dr Alison. “Others are owls, preferring to stay up late and sleeping in a little later as well. Whether you are a lark or an owl is also genetically determined.” You can always try and override your natural sleep timing but this would leave you feeling tired.
Duration
Naturally, nap for a short period of time and wake up ready to hit the gym? You’re a naturally short sleeper. If you naturally prefer a lie-in and like going to bed later at night, that’s your natural duration. “It is important to accept the duration of your rest, otherwise it is can lead to a lifetime of medication with no real change in your sleep,” says Dr Alison.
Solidity
Lastly, Dr Alison says there’s also a misconception that zzz’s happens in one solid block – uninterrupted from start to finish. “Solidity of sleep refers to the expectation that rest during the night should occur in one solid block,” she says. “However, that never really happens because we actually wake up every 90 minutes.”
According to Dr Alison, these wake-ups are very short and good sleepers don’t even remember them. It is believed that we wake up just to check the environment – an evolutionary “safety feature”.
“If you extend your duration by an hour, those wake-ups are also likely to expand, meaning that when you wake up normally you may stay awake for longer,” she says. “Sometimes, the first three hours of bedtime stay intact with multiple awakenings after that.”
While many assume that any period spent awake during the night must be abnormal, Dr Alison says that literature from centuries ago suggests that it was normal to go to sleep as soon as it got dark, followed by a few hours spent awake during the night and another few hours of sleep before starting the day. “So, sleep would be in two pieces – and that was normal,” she says.
What about tech?
While you might be using blue light blockers to minimise your blue light exposure before bed, what about smartwatches that track your zzz’s? Dr Alison says it’s a useful tool to use. “Smart devices can give us lots of information about our sleep,” she says. “Analysis has been done on many of them looking at how accurate they are compared to the gold standard – a full overnight sleep test. They match up quite well but can be up to 40 minutes off when analysing sleep stages.” So don’t go overboard when using them as the absolute truth of your rest – it might be off by a few minutes when letting you know how many hours you’ve slept.
They can also give valuable insights in sleep apnoea and heart rate levels during rest, says Dr Alison. “If your heart rate during the night is high and your oxygen is very variable – that is not normal.”
Our top sleep-tracking watches
Huawei Band 7
With 96 workout modes and a two-week battery life, you can’t really go wrong. It tracks sleep and can identify up to six sleep-related issues.
Fitbit Sense
Track your time spent asleep in various sleep stages and use the app to create a personalised wind-down routine that’ll keep you accountable.
Garmin Venu Sq 2
Understand how your body is recovering with our improved sleep monitoring feature. After waking up, you’ll receive a sleep score as well as breakdown of your sleep stages.
