Sleep – vital to good health

Published: 08 Jul 2016

Sleep – vital to good health

Did you know it’s Sleep Awareness Week?  Why you may ask?  Did you know that sleep is vital for mental health, physical health, quality of life and safety?  It also supports growth and development in children and teens.  Are you getting enough?  Probably not!

Not enough sleep – what then?

Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. This can be gradual over weeks or it can be gained from pulling an all-nighter. People with sleep debt take longer to finish tasks, have a slower reaction time, and make more mistakes. After several nights of losing sleep, even a loss of just 1–2 hours per night, your ability to function suffers as if you haven’t slept at all for a day or two.  Have pity on parents of small children who may be sleep deprived for years!

Sleep helps with memory and emotional health. Sleep helps you to create pathways which assist you with remembering and learning.

Being sleep deficient can lead to poor decision making, problem solving, emotional control and behavioural control. It has also been shown to increase the risk of depression, risk taking behaviour and suicide.

Sleep also helps with physical health. Sleep helps control hormones that make you feel hungry (ghrelin) or full (leptin) it also controls hormones that controls your blood glucose (sugar) level. In fact being sleep deficient is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes and stroke.

So how much sleep should you be getting?

Below is a graph by the national sleep foundation detailing the amount of hours recommended for a specific age. The dark blue is the recommended amount, light blue also shows the amount of sleep which may be also be appropriate, the orange shows what is not recommended.  People of the same age might sleep for different amounts, this is often due to genetic predisposition.Sleep Week

Is there such a thing as too much sleep?

Yes! Over sleeping can be just as bad as not getting enough, so finding the sweet spot is vital.  Over sleeping messes with your circadian rhythm, a 24-hour cycle that is driven by your biological clocks and results in physical, mental, and behavioural changes. This can lead to feelings of lethargy, fatigue, and drowsiness (similar to jet lag). It has also been associated with higher rates of lower back pain, stroke, diabetes, and heart disease.

Did you know…

  • Humans spend a third of their life sleeping. That’s about 25 years so a comfy mattress and pillow are worth it!
  • Man is the only mammal that willingly delays sleep.
  • The majority of muscle growth and repair occurs during sleep when hormones are released. Without adequate sleep muscle gain is greatly diminished.
  • We naturally feel tired at two different times of the day: about 2:00 AM and 2:00 PM. It is this natural dip in alertness that is primarily responsible for the post-lunch dip.
  • A short nap is usually recommended (20-30 minutes) for short-term alertness. This type of nap provides significant benefit for improved alertness and performance without leaving you feeling groggy or interfering with night-time sleep.
  • A new baby typically results in 400-750 hours lost sleep for parents in the first year.
  • Anything less than five minutes to fall asleep at night means you’re sleep deprived. The ideal is between 10 and 15 minutes, meaning you’re still tired enough to sleep deeply, but not so exhausted you feel sleepy by day.
  • Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%. Don’t drive when tired!
  • The “natural alarm clock” which enables some people to wake up more or less when they want to is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up.
  • The record for the longest period without sleep is 11 days.
  • Sleeping on the job is acceptable in Japan, as it’s viewed as exhaustion from working hard.
  • Ongoing sleep deficiency can change the way in which your immune system responds. For example, if you’re sleep deficient, you may have trouble fighting common infections.

More information?

Tom Hamilton Physiotherapist







Tom Hamilton is a Physiotherapist.  He loves to sleep as much as the next person!