The power of a good night’s sleep
THE cooler months make it easier to bunker down and get a good night’s rest but for many, work and ingrained habits, often involving screens, override our natural circadian rhythm’s need to rest and repair. One hundred years ago, less than 2% of the American population slept six hours or less a night. Now, according to neuroscientist Matthew Walker, almost 30% of all developed nations experience sleep deprivation.
Dr Satchin Panda, who is an author and researcher in the area of circadian rhythms, says that sleep loss, over time, leads to four major effects on our circadian code. They are:
1. Insufficient sleep doesn’t give our brain enough time to consolidate memories.
2. Staying up late reduces brain function and productivity that evening.
3. When we sleep less, we are exposed to additional light and the opportunity for eating late into the evening, both of which disrupt the circadian rhythm.
4. The following morning, as we sleep in and rush to work, we have little time to get the necessary amount of morning light exposure needed to brighten mood.
Abnormal circadian rhythms have been linked to various sleep disorders including insomnia, as well as obesity, type2 diabetes, depressed mood, bipolar disorder and seasonal affective disorder.
There are real benefits to achieving the prescribed number of hours of sleep. From tracking a million individuals, researchers have identified a pattern, known as the ‘‘U curve of sleep and longevity’’. People who consistently sleep too little are more likely to die sooner than those who get a full seven hours of sleep each night. Similarly, people who sleep 1011 hours are also likely to live shorter lives. Therefore, too much or too little sleep can be detrimental.
The human body begins to get ready for the day the night before. This is why, when we are in good health and have the correct amount of sleep, we wake feeling refreshed.
Great sleep is created when there are cycles of quiet sleep and active sleep. The quiet sleep takes place in three stages that occur in a specific sequence: N1 (drowsiness), N2 (light sleep) and N3 (deep sleep). Unless something disturbs the process, you will proceed smoothly from one stage to the next, and as you do, your body and brain perform
different functions depending on your circadian clocks. The main causes of a fragmented sleep are dehydration, room temperature being too hot or cold, acid reflux caused by eating too late in the evening, a pet/child, and snoring or sleep apnoea or other noise.
A good night’s sleep ensures better performance the next day. It puts you in better alignment with your circadian code by increasing growth hormone production while you rest, rejuvenating your brain and body. It also increases cortisol production in the morning, which helps with alertness, and balances your hunger and satiety hormones for stronger, more efficient metabolism. Best of all, it synchronises all of your internal clocks so that your whole body is working at peak performance.