Two things we know for sure about sleep: 1) Getting enough sleep is good. 2) Not getting enough sleep is bad. But do you understand why?
It is estimated that 50-70 million Americans suffer from sleep-related problems. The issue is so widespread, the CDC has labelled insufficient sleep a “public health epidemic”.
So let’s dig into the science of sleep – all the good stuff that’s happening to your mind and body while you’re snoozing, and some of the bad stuff that happens when you don’t get enough. But first things first...
Is the 8 hour rule actually a thing?
You’ve probably been going by the 8 hour “rule” without even knowing why or where that came from. You should always listen to your body, but if you’re after a number to aim for, the folks at the Sleep Foundation have done the research. Here are their baseline recommendations for sleep, depending on age:
Newborns (0-3 months): 14-17 hours each day
Infants (4-11 months): 12-15 hours each day
Toddlers (1-2 years): 11-14 hours each day
Preschoolers (3-5): 10-13 hours each day
School age children (6-13): 9-11 hours each day
Teenagers (14-17): 8-10 hours each day
Younger adults (18-25): 7-9 hours
Adults (26-64): 7-9 hours each day
Older adults (65+): 7-8 hours each day
We won’t even bother asking if you could do with getting a bit more sleep. We all could!
Our sleep visualizations will help you get more shut-eye. Drift off to Forest Rain with Michael Olajide Jr.
Lots of good stuff happens while you're sleeping – honestly, there isn't really a downside to getting adequate sleep. But here are four of the best outcomes that you'll see from plenty of shut-eye.
1. You repair and grow muscle!
It’s during the deepest stage of quiet sleep that physiological changes occur, so whether you’re training to build mass or powering through intense HIIT sessions, make sure you’re jumping into bed nice and early to max your muscle.
2. Your immune system functioning gets a boost.
This is another physiological adaptation your body gets to work on during quiet sleep – your immune system releases little protective cells that help counter inflammation, infection and the effects of stress.
3. Your learning and memory is enhanced.
It’s during the REM (rapid eye movement) stage of sleep that you dream – and this your brain’s way of sifting through all the information you came across during the day and banking it for future use.
4. Your emotional and mental well-being is improved.
The why and how is complex (we’ll come to that soon), but it is known that the REM stage of sleep also contributes to positive emotional health, which can prevent and relieve mental health disorders.
Remember how we said no sleep is bad? Not exactly groundbreaking news, we know. But here are four negative outcomes that can come from a lack of consistent sleep – do you any of these look familiar?
1. It “wreaks havoc in the brain”
– as the team at Harvard put it. You probably already have a few words to describe how you feel when you haven’t slept: cranky, short-tempered, clumsy, brain-fog. But what’s actually going on is the level of stress hormones (cortisol) in your body is increasing, impairing your thinking and emotional regulation. This can lead to a vicious cycle of stress and increasing insomnia.
2. You may gain weight!
You’re not going to perform at your best in a workout when you’re running on a lack of sleep. This poor performance can compound the impact a lack of sleep is having on your hormones – driving your hunger up and sending you into snacking overdrive. Next thing you know, your fitness goal is going backwards.
3. You could develop long-term health problems.
According to the NHS in the UK, when you consistently don’t get enough sleep you’re increasing your risk of obesity, type 2 diabetes, high blood pressure and heart disease. Many of these medical issues are weight and diet related, so you can see how a lack of sleep piles problems on top of problems.
4. Your sex drive could plummet.
That’s right, if you’re not getting busy sleeping in bed, you’re less likely to be getting busy in bed! Lack of good quality sleep lowers the libido of both men and women. It can also decrease fertility. So your partner and your family are counting on you to get some rest.
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