We all should know by now that sleep is important, often as or more important than over-exercising. But.. what are the important sleep phases and how do they help us maintain good health?
Our sleep cycle is made up of the following things:
- REM sleep
- Light sleep
- Deep sleep
I have recently started wearing my Garmin at night to see what sleep data it produces. Where google nest gives some data, it is a little less a accurate and a bit more vague than the data Garmin gives, based on HR and respiration rate using a sensor on the back of the watch.
REM sleep phase
What is it?
This is the sleep phase where most dreams occur. During REM sleep, the brain activity, breathing, blood pressure and HR increase and we go into a rapid eye movement phase.
This is when your brain handles the information you have taken in during the day, processes it emotionally and stores it in your long term memory.
About 20-25% of your sleep time should be REM sleep. However, the amount we need does decrease with age.
Symptoms – insufficient REM sleep
- Concentration difficulties
- Excessive daytime sleepiness
- Forgetful or poor memory
Causes of insufficient REM sleep
- Caffeinated drinks, diet pills and decongestant meds
- Certain medications including anti depressants
- Smoking
Ways to improve REM sleep
- Sufficient hydration
- Get a massage
- Blue light blocking (screens!!)
- Read in bed before sleep
Light sleep phase
Physically, here’s what happens. Your rapid eye movement slows, there are periods of muscle relaxation mixed with muscle contraction. Your HR slows and body temperature lowers. Brainwaves slow down.
This is the transitional phase.
As we age we tend to get more light sleep and less deep sleep, losing about 10-12 minutes per decade as our bodies produce lower levels of growth hormone and melatonin. Total sleep time reduces too, as we get less deep sleep and wake more often.
Light sleep suppresses our senses and prevents us from owing so we can remain asleep. It is also important for memory and motor skills.
Deep sleep phase
Deep sleep is the slow wave sleep phase. Electrical activity in the brain is in long slow delta waves. Body functions such as breathing and heart rate are also very slow and your muscles are relaxed. It can be difficult for someone to wake you up and waking out of this phase can make you feel mentally foggy for up to an hour.
This is when your body releases growth hormone and works to build and repair muscles, bones and tissue. It also promoted immune system functioning and replenishes energy stores.
In addition it is also important for regulating glucose metabolism.
During this phase harmful waste products are removed from the brain. This is why disruptions of this sleep phase may also drive advancements in conditions such as Parkinson’s and Alzheimer’s disease.
Symptoms – insufficient deep sleep
- Increased appetite for high calorie foods
- decreased immune response
- Possible links with insulin resistance and therefore type 2 diabetes and heart disease
- Slowed thinking
- reduced attention span
- Worsening memory
- Lack of energy
- Poor or risky decision making
- Mood changes such as increased stress, anxiety or irritability.
Causes of insufficient deep sleep
- Stress
- Aging
- Certain medical conditions such as Alzheimer’s and schizophrenia
- Pain / discomfort
Ways to improve deep sleep
- Regular exercise
- eat more fibre
- Avoid caffeine 7 hours before bed (yes really!)
- Create a relaxing bedtime routine
- Keep your sleep space cool and dark
Thoughts and takeaways
So there you go people, its true. Lack of the right type of sleep can make you fat! Hahaha
Seriously though, I would definitely agree with a lot of the information above (which is researched fact, not just my opinions). I have struggled with sleep for a very long time. The factors that have been in play for me is pain and stress.
Once the pain was removed (along with my left foot) the stress remained – at very high levels for a number of years. It has only been relatively recently that I have started to consciously notice my stress and anxiety have started to reduce a little. Along with that, I have noticed my deep sleep phase has increased a fraction and become a little bit more consistent.
REM sleep is still inconsistent for me, but I think some of my medications are in play here. However on the whole, I feel a lot more refreshed and restored if I have had decent deep sleep. I consider that to be the most important thing from my personal experience.
As always, I welcome your thoughts, comments and questions.
Melanie Magowan – The Body Mechanic