Sleep is the way we recharge our batteries. We do it for around 6-9 hours per night. Much of it is still a mystery, but scientists have discovered a fair bit.
PATTERNS OF SLEEP
Scientists tend to split sleep into two main types. The first is nicknamed REM (Rapid Eye Movement sleep). In some ways this is closer to a waking state. Brain waves are faster. We move our eyes around a lot, and seem to dream during this time. Our limbs are programmed to stop moving so that we cannot act out our dreams. It bears a lot of similarity to a quasi-hypnotic state, common in animals, called ‘tonic immobility’.
The second is NREM (Non-Rapid Eye Movement sleep). Here, we do not move our eyes around so much, and we move from lighter sleep to deep sleep. In deep sleep, our brain waves become very slow and synchronised, an we are hard to wake. Most deep sleep happens early in the night. It’s important for regeneration and recovery, but we only need a small amount of it. We cycle between REM and NREM sleep.
Sleep happens pretty automatically. Your body clock is programmed, on a roughly 24-hour cycle, to get tired by nightfall. The cycle is entwined with the light-dark pattern caused by the Earth’s rotation. This 24-hour cycle is enhanced by changes chemical balance through the day.
FUNCTIONS OF SLEEP
Sleep is a physical and mental regenerator. Mentally, it helps your thinking and memory. Physically, it helps your general health and immune function.
- Sleep helps you to be attentive the next day (lack of sleep will stop you being able to focus).
- Sleep helps you to think clearly (lack of sleep will increase confusion).
- Sleep helps you to react swiftly (lack of sleep will cause delayed reactions).
- Sleep helps you to stay in good body shape (lack of sleep is associated with obesity).
- Sleep helps your heart to stay healthy (lack of sleep is associated with heart conditions).
- Sleep helps your mental health (lack of sleep is associated with poorer mental health).
- Sleep helps your brain and body to re-balance and co-ordinate itself
- Sleep acts as a kind of cognitive ‘reset button’
- Sleep allows enough energy economy for body regeneration
- Sleep allows a stale mind to enrich and refertilise itself
TIPS FOR BETTER SLEEP
- Make your bed and bedroom comfortable..
- Create a regular daily timetable which includes time to wind down for sleep.
- Increase exposure to light in daytime, and reduce exposure at night – this reinforces your 24-hour rhythm.
- Exercise during the day – this increases your body’s tendency to fall asleep easily.
- Avoid caffeine, or only have it in the morning (it keeps you too active at night).