Sleep is undeniably important for our well-being no matter our age. It is what helps us heal, grow, recharge, learn, and so much more. The amount of sleep we need is mainly determined by our age and also our health condition. But how much do we actually need to sleep to make sure it is enough and is there actually something such as “too much sleep”?
How Much Sleep Do Different Age Groups Need?
The National Sleep Foundation’s (Hirshkowitz et al. 2015) sleep time duration recommendations are as follows:
During our sleep we go through different phases that repeat over 4 or 5 cycles (read more in our “4 Stages of Sleep” blog post). It is important that we get our full recommended sleep because different phases last for a varying amount of time in different phases. For example, the REM phase, which helps us recharge emotionally, process information, and build memories, lasts significantly longer in the latest parts of our sleep. This means that if we cut our usual 8-hour sleep by 2 hours, we cut one quarter of our total sleep but up to half of our REM sleep, which can have negative impact on our emotional and mental health.
The Negative Effect of Not Getting Enough Sleep
You might probably be familiar with the common signs of sleep deprivation such as feeling physically weak, having trouble concentrating and remembering, and feeling drowsy throughout the day. However, there might be some effects that you have not yet connected with sleep problems. For example, the above-mentioned lack of sufficient REM sleep can cause problems with your learning because the memory processing that happens during it is responsible for creating long-lasting memories. People that have insufficient sleep might find it harder to recover from intense physical activity because during deep sleep the body releases the growth hormone that allows our cells to repair, our tissues to regenerate, and our bodies to grow.
Lack of sleep can also have some more bleak consequences such as increased mortality rate (Cappuccio et al. 2010). The study firmly states that this increase in mortality rate is consistent regardless of age, socioeconomic status, and the definition of short duration of sleep (<5, <6 or <7 hours per night). Moreover, this increased mortality rate is seen not in people that sleep too little but also in those sleeping too much! Those sleeping more than 10 hours per night can have similar negative effects to people sleeping 5 hours per night. Neuroscientist and psychologist Matthew Walker, however, explains that this can be due to two potential causes. The first is that people with severe diseases and illnesses tend to sleep longer and stay in bed for longer, and the increased mortality rate is due to the illness, not the longer sleep. The other explanation is poor sleep quality (which we will discuss further in another blog post) because people with poor sleep quality tend to sleep for longer to overcome said poor quality.
Do You Need More Sleep After Sleeping Too Little?
An interesting thing about sleep is the concept of “sleep debt”. We’ve all been there- an amazing party that had us stay up late or an early morning meeting, for which we had to wake up earlier than usual, we cannot reach our optimal hours of sleep every single night without fail. However, when we shorten our sleep by an hour or two, our bodies expect us to “pay it back”, meaning that next time you sleep you will need longer to fully recharge. This is especially true for periods of sleep deprivation that last for a couple of days. After them, our bodies would need a few days of longer sleep in order to be back on track.
A healthy lengthy (but not too lengthy) sleep is crucial for our physical and mental health. Our busy work lives and even busier social lives often get in the way of a good night’s sleep but we should find ways to prioritize finding time to recharge. If you want to learn more about your sleep you can read our other blog posts or subscribe to our newsletter to get the latest information on sleep and announcements when we publish a new post. Also make sure you follow us on social media where we regularly share information on the topic of good sleep practices and more. Good night!