This excerpt is from Inside Source, the newsletter of the Calgary Police Service (Volume 4, Issue 4, May/June 2005).
Humans require six to eight hours of sleep every 24 hours to restore memory and concentration, physical and emotional function. People have individual needs for amount of sleep and their own circadian sleep phase (the timing of their sleep rhythms).
Humans are also diurnal mammals, which means they prefer to be awake in the day and asleep at night. Day sleep has been clearly shown to be shorter and less efficient than night sleep. One's resistance to sleep deprivation is a function of age, environmental distraction, and internal or external stimulation. As we age (usually as we enter the mid-40s), we become less able to tolerate the effects of acute and chronic sleep deprivation.
Substantial research from NASA and the U.S. military in both acute and chronic sleep deprivation protocols has established that there is a significant impairment in cognitive function following 15 to 17 hours of sustained wakefulness.
Shift work imposes a state of both acute and chronic sleep deprivation as well as chronic circadian dysrhythmia (a disruption of the body's biological clock that may feel like jet lag). Being deprived of sleep has a serious negative effect on police performance, which requires a high level of alertness and attention.
Shift workers can take action to avoid incurring additional sleep debt, above and beyond the debt imposed by the nature of shift work.
The adage "Protect Your Sleep" is the fundamental cornerstone of successfully managing the impact of shift work on the patrol officer.
How to protect your sleep:
- Determine how much sleep you need to feel well rested on a daily basis. Multiply that number by 7. The resulting number is the amount of sleep you need per week.
- Determine how much sleep you get. Add up the total amount of sleep you get on day/afternoon/evening shifts per week and night shift per week. Then determine your sleep debt in each situation by subtracting those numbers from your sleep need.
- Focus on minimizing your total sleep debt by taking the following actions:
- Improve your day sleep environment.
- Catch up on your sleep on your days off.
- Learn to catnap.
- Sleep longer during the day when you have a night rotation or tour of duty.
- Give yourself a quiet, completely dark, comfortable day-sleep environment with no distractions.
- Try to get two three- to four-hour blocks of sleep during the day when you work the night shift.
- Learn to catnap. Take a short 20–30 minutes of time with eyes closed, situated in a comfortable and resting position. You do not have to sleep to get the benefit of a catnap.
Remember: The treatment for sleepiness and fatigue is SLEEP!
About the Author
Charles Samuels is the medical director at the Centre for Sleep and Human Performance in Calgary, Alberta, and a clinical assistant professor at the University of Calgary, Faculty of Medicine.
About This Article
This article appeared in NIJ Journal Issue 262, March 2009, as a sidebar to the article Sleep Deprivation: What Does It Mean for Public Safety Officers? by Bryan Vila, Ph.D.