What Is Sleep, and Why Do We Need It?
Sleep seems to be as important to our health as diet and exercise – without it we cannot function properly and may even become ill.
We do know when we sleep, our bodies rest – conserving energy and decreasing blood pressure, heart rate, breathing and body temperature, but our brains remain active – laying down memory, restoring daytime mental function and carrying out tasks that lead to physical growth.
Lack of good sleep can lead to excessive daytime sleepiness, tiredness and lethargy, morning headache, poor memory, anxiety and depression. People who regularly don’t sleep well are also more likely to have accidents, abuse substances such as alcohol, and suffer greater illness and disease.
The type and duration of sleep we have changes during our lifetime.
Benefits of sleep are not just mental, scientists believe sleep can:
- control body temperature and energy use (metabolism)
- keep the immune system working
- control brain function and restore memory
- keep the heart and blood vessels healthy
- repair tissues and stimulate growth in children (growth hormone released during sleep is responsible for both)
- regulate appetite and weight and control blood glucose levels.
Make regular deposits to your sleep bank!
Getting enough sleep can be likened to banking your savings – if you take sleep out of the account, you have to put it back to restore the balance, theres no other way to catch up. Lack of sleep night after night leads to sleep debt, where your performance and sleepiness both get progressively worse.
When this happens, your attention, learning and physical performance all suffer. REM sleep in particular has been linked to learning and to creating new memories. To restore your sleep balance, you need at least two nights in a row of unrestricted good quality sleep.