Considerations for shift work
Sleep loss and insufficient sleep associated with Charge of Quarters (CQ), Staff Duty, and shift work places Soldiers at risk for motor vehicle or work-related accidents and impaired decision-making and reduced alertness. For those sleeping during the day, locate the sleep zone away from noise and traffic. Reduce or redirect traffic away from areas where shift workers sleep and understand that shift work personnel are at increased risk for insufficient sleep.
- Separate sleep areas based on shifts minimizes disruptions.
- Enforce "lights out" and quiet hours policies.
- Coordinate with dining facility to ensure shift workers are able to get their meals without sacrificing sleep time.
The brain's alertness clock (circadian rhythm) is at its lowest point (circadian trough) during the hours of 0500–0900. During this period, Soldier alertness is compromised and Soldiers are at greatest risk of lapses in attention and uncontrollable sleep episodes. CQ and Staff duty should NOT end during the 0500–0900 timeframe because doing so places Soldiers on the road at a time when they are at greatest risk for POV accidents.
- Recommendation: End staff/CQ duty at 1100 hours. This is the ideal circadian/physiological time to end an extended/overnight duty.
- Encourage personnel on CQ to sleep if the mission allows.
After 24-hour duty, employ risk mitigation strategies such as napping after duty as well as prior to driving home. Another option is to drive the Soldier home by an alert staff duty driver or spouse.
Strategies for daytime sleep for shift workers
Daytime sleep can be divided into 2 periods: one in the early morning shortly after coming off duty, and a second period in the afternoon during the mid-afternoon lull in alertness.
Suggested guide for Staff Duty or CQ
Two 12 hour shifts
1100 to 2300||
2300 to 1100|
Commute to/from CQ duty outside of circadian trough.||
Commute to/from CQ duty outside of circadian trough.|
Delayed reporting to duty allows personnel to sleep-in and attend to personal matters before duty starts.||
Driving to and from duty occurs during period of decreased motor vehicle
traffic and minimizes risk of POV accidents.|
Alertness tactics||Encourage Soldier to sleep-in on morning of duty and delay reporting to
work until beginning of CQ/Staff duty.||Encourage Soldier to nap in the late afternoon or early evening prior to
reporting to duty shift.|
Return to duty||
Next day return possible with late arrival (e.g. 1000) to allow for sleep recovery.||
1 day off prior to return to allow sleep recovery.|
One 24 hour shift
1100 to 1100|
Commute to/from CQ duty outside of circadian trough.|
Secondary benefits||Delayed reporting to duty allows personnel to sleep in and attend to
personal matters before duty starts. Driving to and from duty occurs during
period of decreased motor vehicle traffic and minimizes risk of POV accidents.|
Alertness tactics||Dose caffeine starting at approximately 2300h if the mission does not
permit on-duty sleep.|
Stop caffeine at least 6 hours prior to post-CQ sleep.
If on-duty sleep is possible, sleep as long as possible. Best sleep periods are
in the early to mid-afternoon lull and morning circadian trough.
Use alternative sleeping facilities for those on duty.
Afternoon sleep prior to duty (more sleep is better).
Return to duty|
|1 day off prior to return to allow sleep recovery.|
Effects of light on alertness
There is some evidence that sources of light found in office and at home (e.g. light from computers, smart phones and other hand-held electronics), boosts alertness (and interferes with sleep)
Use bright electric light – especially light sources that simulate natural sunlight – to boost alertness, particularly for shift workers. Research has shown that using this lighting improves alertness and reduces accidents.
While this alertness boost may be useful for night and shift workers, it is a double-edged sword since it can also subsequently lead to poor sleep quality and duration.
There are several tools that can be used to minimize light exposure to maximize ability to sleep.
To date, only three devices have evidence that they block light and improve sleep:
Dynamic screen controller
Article comparing LED lamps
Glasses and lamps
NOTE: Use of trademarked name(s) does not imply endorsement by the U.S. Army but is intended only to assist in identification of specific products.
SLEEP TACTICS FOR SUSTAINED OPERATIONS
Sleep in a Tactical Environment
Sleep is critical for sustaining the mental abilities you need for success in training and on the battlefield. Even simple tasks such as communicating, driving, or plotting grid coordinates can be impaired by inadequate sleep (anything less than 7hours of sleep every 24 hours). Soldiers can correctly sight a target – but they might select the wrong target.
Planning for sleep in training and tactical environments is a core leader competency. Leaders must know the sleep-work cycles of their Soldiers, particularly when they are working shifts, are in operational environments, or are outside standard duty hours.
Combat operations can create situations where inadequate sleep becomes the norm. Soldiers who do not get enough sleep accumulate a sleep debt that must be paid off by making up the needed sleep. It's mission-critical to make sleep a top priority.
Inadequate sleep impairs the following abilities, among others:
- Detecting and appropriately determining threat level
- Requesting indirect fire
- Coordinating squad tactics
- Integrating range cards
Signs of insufficient sleep:
- Struggling to stay awake during mission breaks, guard duty, or driving
- Difficulty understanding or tracking information
- Attention lapses
- Irritability, decreased initiative/motivation
Sleep tactics for sustained operations
|Get as much sleep as possible the week before the operation so that you start the mission with as full a sleep bank as possible (e.g., 10 hours/night).|
|If possible, get 7+ hours of sleep every 24 hours.|
If 7+ hours is not possible, take naps when mission permits to minimize your sleep debt.
Use caffeine to temporarily sustain mental performance until you can obtain sleep.
|After Operations||Get extra sleep each day to pay off your sleep debt and resupply your
sleep bank (e.g., 10-12 hours/night).|
Caffeine use during sustained operations:
Daily use of caffeinated products is very common and can be useful in the morning to promote alertness in sustained operations. In day-to-day life caffeine intake should be restricted to morning use to temporarily reduce sleepiness and maintain performance. Remember, caffeine content varies depending on the product.
Refer to the section: Sleep Deprivation Countermeasures, for a caffeine dosing schedule.
Night operations and performance
The figure below shows how the brain's biological clock impacts sleep/wake and performance. The brain's clock is programmed to boost alertness during the day and sleepiness during the night.
Daytime work / Nighttime sleep
The figure below shows what happens on night shift work
. This clock is slow to adjust and often never adapts to night time operations. Soldiers working across the night are trying to stay alert when their brain clock is programmed to sleep. During the period from about 0600 to 0800, leaders and Soldiers are especially error-prone. After the night shift, Soldiers are trying to sleep when their brain clock is programmed to be awake. Their ability to sleep is impaired, resulting in a reduced sleep duration and sleep debt.
Nighttime work / Daytime sleep
Managing Sleep to Maintain Performance
Sleep does not have to be taken in one continuous period to be effective. It is preferable to give Soldiers uninterrupted sleep time at night when the brain clock is programmed for sleep. But two periods that add up to 7 or more hours of sleep every 24 hours also works. Naps can be taken to compensate for insufficient nighttime sleep.
Bottom line: Do not create schedules or situations in which Soldiers are forced to choose between adequate sleep and other off-duty activities (personal hygiene, calling home, meals etc.) They will always sacrifice sleep in these situations.
If sleep must be rationed
Prioritize sleep need by task:
- TOP PRIORITY: Leaders making decisions critical to mission success and unit success.
- SECOND PRIORITY: Soldiers who have tedious or sedentary duties such as monitoring equipment for extended periods or guard duty, and those who judge and evaluate information.
- LOWEST PRIORITY: Soldiers performing duties involving only physical work.
Sleep Recovery after Sustained Operations
Following any period of insufficient sleep, leaders and Soldiers need extra sleep to fully reset and pay down their sleep debt. Although exact amounts of sleep required to fully recover are unknown, we do know that the longer a Soldier goes or has gone without adequate sleep, the more nights will be needed to fully recover. We also know that recovery from a single bout of sleep loss is faster than recovery from chronic insufficient sleep.
- Following a single bout of sleep loss, most Soldiers will recover adequately if allowed 1–2 nights with as much time in bed as desired.
- Chronic, inadequate sleep (less than 7 hours of sleep across 3–6 nights or longer) requires 5 or more nights of unrestricted recovery sleep to restore adequate alertness and performance.