There was a time many years ago when overnight rushes of tutorial assignments, DOTA, and rooftop drinking sessions were aplenty. As a student of the biomedical sciences then, I should have known better. For too many youthful years, that lifestyle messed up body clock and sleep cycle. Even though I’ve left that life behind, the lingering detrimental effects of sleep deprivation on my body and mind can still be felt today.
One of the goals I’m currently working towards is to get out of bed before 7.30 am every morning. Initially, this proved to be quite a challenge because I didn’t understand the significance of sleep very well. However, things got better after I chanced upon a video series on TED. Interestingly entitled Sleeping with Science, I found myself becoming more mindful about my sleeping habits, and started to make a more conscious effort into improving the quality of my sleep.
Produced by Dr Matthew Walker, author of the international best-seller, Why We Sleep, the first video in the series walks us through the various stage of the sleep cycle. If you’ve got 5 minutes to spare, I highly recommend that you watch the video below. Otherwise, read on below to see my top three takeaways from this short video!
Key Takeaways:
1. Our sleep cycle is made up of various stages that contribute differently to the daily recovery of our body and mind. 2. We spend different amounts of time in the various stages of the sleep cycle at different parts of the night 3. Disrupting different parts of our sleep will affect us in different ways.
Takeaway #1: REM and non-REM sleep aid our physical and mental recovery differently during our sleep
“Sleep is perhaps the single most effective thing that we can do each and every day to reset the health of our brain and our body”
Dr Matthew Walker
According to Dr Walker, sleep is commonly characterized by the cyclic occurrence of rapid-eye-movement (REM) sleep and non-REM sleep. We can further break down non-REM sleep into four stages, where the later stages are deeper and longer than the earlier ones.
Interestingly, the later stages of non-REM sleep plays a crucial role in the recovery of our body. This is the time when our body repairs and regenerates tissues, and clear toxic waste from the brain. In addition, studies also suggest that non-REM sleep also promote the consolidation and fixation of short-term memory into long-term memory. I wish I had known this earlier; it might have motivated me to take more afternoon naps during my schooling days!
On the other hand, REM sleep appears to boast a variety of health benefits. According to various studies, these may include improvements in cognitive brain function, lowering of blood pressures, and better management of depression and anxiety. Dr Walker also suggests that REM sleep has positive influences on creativity and problem-solving. This might explain why we were able to come up with solutions to challenging problems the night before after we have “slept on it”.
Takeaway #2: We spend different amounts of time on non-REM and REM sleep during the night
“… it turns out that non-REM and REM [sleep] will play out in a battle for brain dominance throughout the night…”
Dr Matthew Walker
If you were like me, you might think that all sleep is equal. However, I couldn’t be more wrong; for a typical sleep cycle of ~90 minutes, the ratio of non-REM to REM sleep differs throughout the night. In the first half of the night, we experience a greater proportion of late-stage non-REM sleep. Later in the second half of the night, this balance switches over to more REM sleep. This means that longer periods of REM sleep are usually experienced in the final hours of our sleep.
Clearly, clocking a full night’s rest can help us feel rejuvenated in both body and mind. This was a big learning for me as my sleep times usually range between 4-6 hours. Understanding this point is crucial, for it brings me to my third takeaway…
Takeaway #3: Disrupting different parts of our sleep will affect us in different ways.
Since we get more REM sleep during the later stages of our sleep cycle, shortening the overall duration of our sleep will cost us more in REM sleep than non-REM sleep. If we revisit the earlier paragraph on the benefits of REM sleep, it might explain why we tend to be grumpier than usual when we don’t get enough sleep.
Indeed, shaving off two hours from our usual eight-hour sleep windows might only mean a 25% reduction in all of our sleep. However, this might also represent “perhaps 50, 60, maybe 70 percent of all of [our] REM sleep”, as highlighted by Dr Walker. For people with highly irregular sleep times, like parents with a newborn child or those on shift-based work, this insight helps us better understand why disrupted sleep makes us feel like crap in the day.
Closing thoughts
I’m sure there are many folks out there juggling between a day job and a side project/hustle. It is thus common for us to work late into the night and neglect our sleep in the process. Now with a better understanding of the sleep cycle, I feel compelled to cut down on the late-night work and optimize my day for productivity. This way, I might feel better turning in early to ensure sufficient time for my mind and body to recover.
Next up, I’ll share Dr Walker’s take on how caffeine and alcohol can influence the quality of our sleep. It appears to be a common social practice where people drink coffee at midday to help them stay awake, while a cocktail at night helps them de-stress and unwind. As it turns out, there might be misconceptions there! Curious to know more? Stay tuned to find out!
If you felt that you resonated a lot with what was shared above, I’d love to hear from you in the comments below. Feel free to also share this post with your friends on social media! Don’t forget to tag Kopithoughts in your posts!
3 comments
Thanks Terry for enlightening us about the science of sleep. I have been going to the bed before 11:00 pm and waking up around 5 in the morning for a few years. Many people have shared with me that the hardest part is to fall asleep before 11 am. I wonder if readers face the same issues as well? Personally I cease to work on brain stimulating activities (such as work or watching videos) around 9 pm, that helps me to fall asleep faster.
Wow 5am! That’s amazing! Waking up earlier is the bigger challenge for me as compared to falling asleep. Perhaps what might help is to cut down on caffeine-intake in the day, especially after 12pm? 10-12 hours after your last coffee, about 25% of the caffeine is still in your body, and that might make it difficult to sleep earlier.