Diary check-in: look for your body clock
You will be able to: Spot body-clock patterns in your own diary, especially a shift between work days and free days.
By now you should have a few nights in your diary (most people are on day 3 or 4 when they reach this unit). That is enough to start looking for your body clock in the numbers. Keep logging every morning: you are still only watching, not changing anything.
Three clock clues to look for
- Does your wake-up time jump on free days? Compare your "out of bed" times. In this course, a jump of more than an hour is the clock clue to watch most. In one study, a weekend of catch-up sleep after short work-day nights was followed by a later-running body clock, which Monday morning then has to work against.
- When do you feel sleepy, compared with when you go to bed? If you often go to bed before you feel sleepy and lie awake, your bedtime may be earlier than your clock wants. If you are falling asleep on the sofa an hour before bed, it may be later.
- Late caffeine and slow nights. Look at the nights when you took a long time to fall asleep. Did you have caffeine after your new cut-off time that day?
Write one line
On paper or in your notes, finish this sentence:
"So far, the clock clue I notice most in my diary is ______________________."
Do not try to fix it yet. In Module 3 you will read your whole baseline week and choose one pattern to work on.
Sources
- Carney et al. (2012), The Consensus Sleep Diary, Sleep 35(2): 287-302, PubMed 22294820
- Wittmann et al. (2006), Social jetlag: misalignment of biological and social time, Chronobiology International 23(1-2): 497-509, PubMed 16687322
- Depner et al. (2019), Current Biology 29(6): 957-967, PubMed 30827911 (weekend catch-up sleep and a later-running clock)
- NHS, Insomnia (when to see a GP)