“Think in the morning. Act in the noon. Eat in the
evening. Sleep in the night.”
Teenagers tend to sleep either too often or not often enough. When you wake them up, they aren’t exactly in a desirable mood. You probably dislike this pattern of behaviour and call it unreasonable compared to your own happy waking. You think this post-nap moodiness may just be a result of puberty, and the overall common gloomy behaviour present in most teenagers, but the truth is that it happens with everyone and depends on your sleep cycle.
The sleep cycle consists of four stages and averages approximately 90 minutes per full cycle. The first three stages are classified as NREM (non-rapid eye movement) stages of sleep whilst the fourth is REM (Rapid eye movement) sleep. These two types of sleep allow your brain to progress sequentially through each stage.
Stage 1 is the transition from wakefulness to being asleep. Your eye movement, heart rate and respiration begin to slow down and your muscles start to relax. Your body temperature drops and your brain waves slow.
Stage 2 is a very light sleep where your breathing continues to slow down and your muscles relax further. Your eye movement stops altogether as your body prepares for a deeper sleep.
Stage 3 is where your body falls into a deep sleep. Your heart rate and breathing are slowed to their lowest levels in this stage while your muscles are completely relaxed. Your body releases repair hormones and tissue growth and cell repair will take place in this stage.
Stage 4 is the REM stage of sleep and as can be inferred from its name: your eyes will move rapidly from side to side under your eyelids in this stage. Your brain wave activity has mixed frequency and gets closer to your wakefulness state. Your breathing, blood pressure and heart rate increase to near waking levels. Most of your dreams occur in this stage and your muscles are paralysed to ensure you do not act out your dreams. The REM stage of sleep increases in duration as the night (or your nap) goes on and, since your brain processes and synthesises your emotions and memories in this stage, it is important to get longer amounts of sleep.
While it may seem counter-intuitive, sleeping for 6 hours will lead you to feel better rested and awakened than if you woke from an 8-hour slumber. This is because after 6 hours, you will likely be at the end of a sleep cycle whereas after 8 hours, you will likely be entering stage 3 of sleep. Once woken, you will feel more groggy and disoriented. Therefore, sometimes shorter naps can result in a better mood.
Bangkok Patana School Student
Gordon M. Amie, July 2013, “Your Sleep Cycle Revealed”, Psychology Today [online]
Available at: https://www.psychologytoday.com/intl/blog/between-you-and-me/201307/your-sleep-cycle-revealed
Zakri Jocelyn, March 2020, “Stages of Sleep and Sleep Cycles”, Tuck [online]
Available at: https://www.tuck.com/stages/
Lockett Eleesha, June 2020, “Everything to Know About the 5 Stages of Sleep”, healthline [online]
Available at: https://www.healthline.com/health/healthy-sleep/stages-of-sleep#fun-facts