SLEEP QUALITY

Healthy from the Start Resources for Shiftworkers

Good sleep isn't just about the number of hours; it's also about the quality of those hours, especially for shiftworkers navigating unconventional schedules.

Is all sleep created equal? What is considered ‘quality’ sleep? You can usually tell if you’ve had a good sleep – you’ll wake up feeling refreshed and satisfied, and may not have woken up at all during the sleep period, or only briefly.

From a scientific perspective, quality sleep can be broken down into four factors (8).

QUALITY SLEEP DEPENDS ON…

Sleep Efficiency:

  • This measures the percentage of time you're actually asleep compared to the total time spent in bed. For instance, if you're in bed for 10 hours but only sleep for 7.5, your sleep efficiency is 75%. An efficiency of 85% or more is considered optimal (9).

Sleep Onset Latency:

  • This is the time it takes to fall asleep. Ideally, it should be between 10-20 minutes. Taking longer could indicate difficulty initiating Stage 1 sleep or that you’re experiencing a sleep disorder, while falling asleep in under 5 minutes often points to excessive sleepiness (10-12).

Sleep Duration:

  • Total sleep time in a 24-hour period is crucial, and doesn’t include the time you spend awake in bed. The goal is 7-9 hours, preferably in one stretch. As a shiftworker, if a continuous sleep period is challenging, strategically timed naps can help boost the amount of sleep you get each day (1).

Wake After Sleep Onset (WASO):

  • This refers to periods of wakefulness after initially falling asleep. Brief awakenings during your sleep period are normal, often occurring as you transition between sleep cycles. However, being awake for more than 5% of your total sleep time, for example more than 20 minutes during a 7-hour sleep, can be a sign of disrupted sleep (13).

It can be difficult as a shiftworker to meet the requirements for 7-9 hours of quality sleep.

As a function of your work commitments, sometimes you don’t have enough time between shifts to get the hours of sleep that you need, so you may sleep for longer on your days off to catch up. This is common amongst shiftworkers, as the extra sleep is chipping away at the ‘sleep debt’ that you may have accumulated during your run of shifts. However, while this may be common, it doesn’t replace the benefits of 7-9 hours of sleep each day, so it’s important to try to achieve this as much as possible (14).

Sleep is complex, but thankfully the human body has special systems that help you to fall asleep, stay asleep, wake up, and stay awake. Your circadian rhythms play a crucial role in regulating sleep and wakefulness. Learning about these rhythms can provide deeper insight into managing your sleep, particularly in the challenging context of shiftwork – read more about them here.