Wednesday, May 8, 2013 7 Comments
Normal cuts a Wide Swath
by Madelyn Griffith-Haynie, CTP, CMC, ACT, MCC, SCAC
Another article in the Sleep Series
Normal Circadian Rhythms
Among people with healthy circadian clocks, there are “Larks” or “morning people” who prefer to sleep and wake early, and there are “Owls” who prefer to sleep and wake at late times.
But whether they are larks or owls, people with normal circadian systems:
- can wake in time for what they need to do in the morning, and fall asleep at night in time to get enough sleep before having to get up.
- can sleep and wake up at the same time every day, if they want to.
- will, after starting a new routine that requires their getting up earlier than usual, start to fall asleep at night earlier within a few days.
For example, someone used to sleeping at 1 a.m. and waking up at 9 a.m. begins a new job on a Monday, and must get up at 6 a.m. to get ready for work.
By the following Friday, the person has begun to fall asleep at around 10 p.m., and can wake up at 6 a.m. feeling well-rested.
This adaptation to earlier sleep/wake times is known as ‘advancing the sleep phase.’ Healthy people can advance their sleep phase by about one hour each day.
24 hours a day isn’t “normal”
Researchers have placed volunteers in caves or special apartments for
several weeks without clocks or other time cues. Without time cues, the
volunteers tended to go to bed an hour later and to get up about an hour
later each day.
These experiments demonstrate that the “free-running” circadian rhythm in humans is [greater than the earth's 24 hour cycle - anywhere from 24:15 to 25 or so a day].
To maintain a 24 hour day/night cycle, the biological clock needs regular environmental time cues, e.g. sunrise, sunset, and daily routine.
Time cues are what keep our body clocks aligned with the rest of the world.
Originally created by Su Laine Yeo ©1996-1998 for her often-used, rarely attributed DSPS articles, generously shared on GeoCities at a time when her information
was about ALL you could find on chronorhythm disorders
She credited the Biological Timing Tutorial
from the National Science Foundation Center for Biological Timing
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while you’re reading. They turn red on mouseover
Hover before clicking for more info
Beleaguered by the Morning Nazis
“Put no trust in the benefits to accrue from early rising,
as set forth by the infatuated Franklin …”
~ Mark Twain
Nevermind the reality that the time-structures of our planet remain set for the convenience of the dawn-to-dusk agrarian work schedules of a much earlier time, there is still a great deal of pressure to wake up EARLY.
Lark or Owl, the majority of individuals in America seem to have decided that there is something intrinsically BETTER about waking in the early morning hours, and something DARK about being awake after midnight.
Night Owls, however, with different native sleep patterns, generally find that we are at our most effective once the sun sets, and essentially worthless in the early A.M. daylight hours — some of us still struggling for cognitive efficiency well-past noon.
Still, much of the world is of the opinion that anyone still a-bed after 8:00 AM is lazy, unmotivated, or avoiding something unpleasant by escaping into sleep — even when we sleep fewer total hours than they do.