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what is
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stage 3 sleep or deep sleep so after
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about 20 minutes in stage 2 of sleep
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your brain and body becomes especially
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relaxed you begin to enter deep sleep
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your muscle tone heart rate breathing
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slow even further and at this point your
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brain activity slows to a minimum
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this results in very slow moving brain
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waves which we call delta waves there's
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only about one or two waves each second
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and this is also why deep sleep is also
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referred to sometimes as slow wave sleep
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during this time you'll be very hard to
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wake up unless you happen to smell
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burning or you hear a very loud noise
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if you do wake up you'll feel groggy
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very groggy and disoriented for several
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minutes
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now we spend the most time in deep sleep
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during the first half of the night
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during the early sleep cycles
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deep sleep stages commonly called in
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three last for around 20 to 40 minutes
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and as you keep sleeping these stages
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get shorter and then more time gets
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spent in dream or rem sleep instead