We all know sleep is integral to healthy physical and mental wellbeing. But have you ever wondered what happens during the 6 to 7 hours of our nightly sleep?
The sleep process is associated with cellular restoration, energy conservation, weight maintenance, insulin production and better heart health. Is this information surprising?
If it isn’t, then the question is why do we compromise our sleep time by routinely staying up late —partying, watching TV or mindlessly scrolling through social media?
If, on the other hand, you would like to know the science behind sleep, read on:
Our body clock
We all have an internal 24-hour timekeeping system known as the ‘circadian clock’. The term ‘circadian’ means that which occurs naturally in a 24-hour cycle. Circadian rhythms regulate our sleep-wake cycle based on exposure to natural light, and influences hormone production and our appetite among other bodily functions. It is controlled by a structure called the Suprachiasmatic Nucleus (SCN) located in the area of the brain known as the hypothalamus.
Our body clock reacts to exposure to light. When retinal cells in our eyes perceive natural sunlight, it transmits signals through nerve tracts that connect to the SCN, initiating the circadian process of waking up. The waking up process involves the secretion of a hormone called cortisol that stimulates wakefulness and awareness.
In the evening, as the sun goes down, our body clock influences the pineal gland in the brain to produce melatonin, the hormone responsible for sleep and relaxation. This is the signal to the body that prepares it for sleep. The whole rhythm starts up again the next morning.
What are the stages of sleep?
The sleep cycle consists of four cycle. The first three stages are known as non-rapid eye movement (NREM) sleep, while the fourth is known as rapid eye movement (REM) sleep.
NREM1: This is the first stage that marks a transition from your state of wakefulness towards sleep. This stage is characterized by light sleep marked by a slowing down of the heartbeat, the breathing rate, eye movements and brain activity. Our bodies gradually enter into a state of relaxation. This stage usually last for several minutes and varies from person to person.
NREM2: In the second stage the body continues in a light sleep with a further drop in heart and breath rate and slowing down of brain activity. There is a significant change in body temperature at this stage.
NREM3: This stage marks the beginning of deep sleep. Heartbeat, eye movements, brain activity now drops to the lowest possible level and muscles completely relax. This is the longest stage in the sleep process.
REM: The final stage of the sleep cycle is REM. In this stage there are rapid eye movements. Brain waves become more active, and the heart and breath rate rise. This is the stage when we usually start dreaming.
A sleep cycle — consisting of these 4 stages — may last between 90 and 120 minutes and depends on age and other factors. We ideally should have around 4 such cycles per night.
This is why an average adult must get at least 7 hours of good quality sleep. When we cut into our sleep hours, it obviously means we are not giving our bodies the time to repair and restore itself. This, in turn, makes us vulnerable to various health risks. The immediate effect is an inability to focus and concentrate.
Yoga offers several techniques that help improve sleep. A daily routine of breathing exercises can work wonders as also Yoga Nidra.
Check our blog How to Improve Your Sleep with Breathing Exercises. Check out our YouTube channel for talk shows that discuss sleep in more detail.
You could also call us and schedule a free evaluation?
Talk to our yoga specialists today. Call 050-395-5613.
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