EXCLUSIVEDear doctor. Why am I MORE tired after a really good night's sleep?
Many of us occasionally forego an extra hour of sleep in order to get to the gym before work, or join an early morning meeting.
But do you ever find that, despite getting less sleep, you're actually more awake than usual?
It's an intriguing conundrum that has recently been explored in certain corners of the internet, including Reddit and TikTok.
In one video that's been viewed more than 30,000 times, TikToker Nathan Beaudinn asked his followers why he has 'way more energy' when he sleeps less.
Meanwhile, on forum website Reddit, one user asked: 'How come I feel less tired and more energetic when I wake up if I get less than seven hours sleep, and if I get more, I wake up feeling miserable?'
Now, experts speaking to DailyMail.com have revealed the fascinating answer.
For most people, getting between seven and nine hours of sleep per night is key to both mental and physical health.
Dr Ankit Parekh studies how people deal with sleep apnea deal with the effects of a poor nights rest. In his research, he's found that patient's brains work harder to keep them alert when they're sleep deprived. This could play a role in giving them the false perception that they're more awake.
They say it is all down to compensatory tricks performed by the brain that are designed to make up for a lack of sleep.
'The body and the brain are trying to adapt to whatever issue or deficiency that they're we're experiencing,' Dr Sam A. Kashani, a board-certified sleep medicine specialist at UCLA Health, told DailyMail.com.
'That's why we've lasted for thousands and thousands of years, because no matter what the stressor may be, whether acute or chronic, our brain and our body is going to always just naturally try to adapt and work around that.'
According to the National Institute for Health, between seven and nine hours of sleep per night is ideal for optimum mental and physical health.
Any less than that and your body, brain and behaviors will adjust to keep you moving when you're not fully rested, Dr Ankit Parekh, an assistant professor of sleep medicine in the Icahn School of Medicine at Mount Sinai told DailyMail.com.
This involves producing extra 'wakeful' chemicals that keep your body alert and temporarily increase your attention span, Dr Parekh said. For instance, cortisol, known as the stress hormone, and adrenaline.
After a healthy nights sleep, most people's cortisol levels peak in the morning and slowly fall throughout the day, according to Dr. David Rosenberg, who practices family medicine in Florida.
But when you get less sleep than you need, you can throw this cycle off, causing your body to produce cortisol at unnatural times, such as later in the day.
This may give the impression that your energy levels are higher than usual in the afternoon or evening, Dr Parekh said.
However, if you're constantly flooded with stress hormones, they can begin wearing on your body.
Chronically high cortisol levels, for example, can lead to high blood pressure, a weakened immune system and high blood sugar that leads to type 2 diabetes, according to Cleveland Clinic.
It also puts extra stress on brain cells and stops them from functioning properly, making you feel more tired in the long run.
'You may feel that you're more alert when you sleep less,' Dr Parekh said. 'But the longer you are going to be awake with that short amount of sleep you will start to feel its effects, and pretty soon realize that you need to recover.'
Studies show that cognitive performance plummets with inadequate sleep — even if you think you're alert.
One study from the University of Pennsylvania and Harvard found that volunteers who've slept badly and perform poorly on learning tests say they feel perfectly awake.
This suggested, the scientists wrote, that the participants were 'largely unaware' of the increasing affects of sleep deprivation.
Dr Parekh says brain scan studies show those who are sleep deprived have to work much harder to focus than people who got a good nights sleep.
Another factor that could influence feelings of wakefulness is anxiety, Dr Kashani said.
The same stressful scenarios that are keeping you up at night, contributing to worse sleep, can sometimes make you feel alert during the day, he said.
This 'viscous cycle' can be hard to break, and though you may feel more alert in the short term, you'll begin netting the harmful affects of sleep deprivation eventually.
Sleep needs change with age and your individual preferences, but professionals almost never recommend getting less than seven hours per night.
Prime Minister Margaret Thatcher famously only needed four hours of sleep a night in order to function. She could've had short sleeper syndrome, an exceedingly rare condition where people need six hours or less of sleep per night and seem to function perfectly well.
Another reason you might feel more awake after less sleep is because you're subconsciously reaching for more substances that stimulate your brain when you're sleep deprived.
If you drink coffee most mornings, for example, you might be grabbing an extra cup without realizing it. The more caffeine you drink, the more alert you will probably feel.
Finally, there's a very small chance that you fall into a rare group of people that function well on less sleep than the average human, Dr Parekh said.
Scientists aren't sure how many people fall into this category - people affected by short sleeper syndrome - but have only conclusively found it in about 50 families around the world, according to Cleveland Clinic.
It's thought to be a rare genetic mutation passed down from parents to children, not something that you develop in life.
Short sleepers, miraculously, get four to six hours of sleep per night and still feel energized. They also tend not to need alarm clocks and have an easy time falling asleep at night.
Famously, Prime Minister Margaret Thatcher is said to have fallen into this category, only needing four hours of sleep a night.
But if you're part of the vast majority of people who need more than four hours, you will over time begin to feel the effects if you're consistently getting less sleep, Dr Kashani said.
In the short term, you're likely to have problems focusing, learning and responding to other peoples emotions if you get less than eight hours according to the NIH.
You might also get frustrated and cranky easier than you normally would, which can make socializing difficult.
The body also becomes more inflamed when it's sleep deprived, Dr Parekh said, which wears down all of our internal systems - from the brain to the heart.
This is likely part of the reason why in the long term, getting less sleep has been linked to heart disease, kidney disease, diabetes, stroke, obesity, depression and high blood pressure, according to the NIH. It's also been linked to degenerative conditions, like dementia, Dr Kashani said.
It can also increase your likelihood of being involved in accidents like car crashes.
All told, Dr Kashani said that too many people 'underestimate' the importance of sleep.
Getting adequate shut-eye is key to supporting your health, he said. Adding: 'the most important sleep habit is to sleep. To sleep as much to sleep as much as your body needs and when your body needs it.'
