From the Front Lines: Trialing Caffeine "Chew Pod" to Mitigate Fatigue

Fatigue continues to be a major area of interest for the Flight Surgeon community. In the Royal Canadian Air Force (RCAF), fatigue is a known threat that degrades operational effectiveness, Flight Safety, and the retention of trained personnel. Managing fatigue requires a multi-layered approach from all levels of command. Under Air Force Order 8008-01, the RCAF Commander has given direction to implement a Fatigue Risk Management System (FRMS) which is a standardized framework that enables RCAF communities to develop fatigue risk control measures. This guidance addresses six layers of defence as described in figure 1.

Figure 2. Caffeine Chew Pod.


On OP IMPACT, Flight Surgeons have been trialing caffeine "Chew Pod" (figure 2) as a pharmacological fatigue counter measure (PFCM) which tackles the alertness

maintenance layer of defence. Though only one part of the broader implementation of the FRMS, this trial has yielded positive feedback amongst participants deployed on operations.


What is it?

The main active ingredient is caffeine and the tablet is coated with a mint flavouring to mask the bitterness of the caffeine. The recommended dose is two chewable tablets (100 milligrams (mg) of caffeine total) which is about the amount of caffeine in a cup of coffee. See figure 3 for an approximation of caffeine equivalencies2.



Through fatigue training and culture building tools.


Through scheduling practices and fatigue prediction tools to optimize workload-personnel balance and sleep opportunities.

Sleep Quality

Through sleep hygiene training, judicious use of pharmacological fatigue counter measures (PFCMs), treatment of sleep disorders, and infrastructure optimized for sleep.

Workplace/ Mission Design

Through appropriately risk managed workplace infrastructure and mission design optimized for maintaining alertness.

Alertness Maintenance

Through fatigue monitoring practices and the use of fatigue countermeasures, including standard fatigue counter measures and PFCMs.

Reporting and Feedback

Through ongoing data collection and analysis to drive continuous program improvement.

Figure 1. FRMS layers of defence. Reproduced from AFO 8008-0.




Serving Size

Caffeine (mg)


8 oz (237 ml or 1 cup)


Roasted and ground, percolated

8 oz


Roasted and ground, filter drip

8 oz


Roasted and ground, decaffeinated

8 oz



8 oz


Instant decaffeinated

8 oz


Average blend

8 oz



8 oz



8 oz


Leaf or bag

8 oz



8 oz



12 oz (355 ml or 1 can)



12 oz


Figure 3. Comparison of caffeinated beverages. Adapted from Health Canada.

How are they used?

Because the tablets are chewed, the caffeine is absorbed through the buccal mucosa (the inside lining of the cheeks and floor of the mouth) allowing for a relatively quick entry (between 5-10 minutes) into systemic circulation3. In comparison, when taken in the form of coffee, caffeine absorbed through an empty stomach takes between 15-30 minutes or an hour longer if taken with a meal.

The RCAF Surgeon has authorized that each trial participant can receive four packages of four doses each, or sixteen doses per month.

A dose of Chew Pod is taken one to four times a day as needed. It is important to note that caffeine merely “shifts” fatigue and is not an appropriate substitute for sufficient quantity and quality of sleep supported by good sleep hygiene. Figure 4 summarizes sleep hygiene principles that everyone should follow to optimize sleep health4.

Who is using it?

OP IMPACT has been selected as the trial site given the operational tempo of the air-to-air refueling (AAR), long range patrol, tactical airlift and tactical aviation detachments deployed in

Kuwait and Iraq. Initially, the Chew Pod was only available to aircrew but, with the positive results collected thus far, the RCAF Surgeon has expanded the trial to include ground crew.

Why are we trialing this?

Fatigue remains the largest preventative cause of accidents in safety sensitive operations worldwide5,6. According to the National Transportation Safety Board, fatigue is a factor in nearly 20% of major accident investiga- tions7. As described above, the RCAF has identified fatigue as a threat that degrades operational capability, flight safety, and the retention of trained personnel. For the individual, fatigue reduces alertness and performance in the short-term and impacts health and well-being in the long-term8. Since it is known that caffeine can increase alertness up to four to five hours9, the RCAF Commander’s direction to implement the FRMS has enabled the Flight Surgeon community to trial this product. This trial studies whether the effects of fatigue can be mitigated by providing a convenient, portable, measurable and rapid dose of caffeine.

Be consistent with timings.

Go to bed at the same time every night and get up at the same time each morning, including on weekends. Depending on operations, this may not always be possible. At the very least, ensure you get “anchor sleep” where you maintain the same four hours of sleep during the same time each day.

Optimize sleep quarters.

Make sure your sleeping quarters are relaxing, dark, quiet and of an optimal temperature. Remove or minimize use of electronic devices such as TV’s, computers and smart phones in your sleeping quarters.

Time your meals.

Avoid large meals before bedtime.

Time your exercise.

Being physically active during the day can assist with falling asleep at night. Avoid exercising right before bed.

Avoid stimulants or alcohol before bed.

Avoid coffee, tea, energy drinks or alcohol within 6 hours of going to bed.

Figure 4. Sleep hygiene principles. Adapted from the Centers for Disease Control and Prevention.

What have we found?

Data was collected from participants through usage of questionnaires. Using the United States Air Force School of Aerospace Medicine (USAFSAM) (Samn Perelli) mental fatigue scale10, self-reported measurements were used to capture fatigue levels. Figure 5 represents the scale with the summed average responses of 14 participants between June to August of 2017.

The tablets were taken by aircrew when they felt it was necessary. Mental fatigue was scored before and after taking a dose. These results demonstrate an average 1.7 point

increase in alertness using this scale. Subjective responses were largely positive and spoke to:

  • Noticeableimprovementsinalertnessand cognitive capability,
  • A quick method of caffeine delivery and effect (~5 minutes),
  • Portability and ease of storage, and
  • A decreased fluid load compared with drinking coffee or energy drinks which meant less trips to the lavatory.

A few participants were not entirely satisfied with the taste but there were otherwise no negative comments.

Flight Surgeons who have joined the AAR crew on flying missions observed two instances where caffeine Chew Pod proved more convenient and accessible than caffeinated beverages for aircrew:

  • During mid-flight when aircrew were occupied with radio communications, and
  • During the critical phase of descent and landing when pilots were often more fatigued after long missions.



When you are asked to “Rate your average mental fatigue (1-7),” fill in the number that is your best estimate of your average mental fatigue across the work period. Use this scale:

Avg after 2.6

1. Fully alert. Wide awake. Extremely peppy.

2. Very lively. Responsive, but not at peak.
3. Okay. Somewhat fresh.

Avg before 4.3

4. A little tired. Less than fresh. 5. Moderately tired. Let down.

6. Extremely tired. Very difficult to concentrate.
7. Completely exhausted. Unable to function effectively.

Ready to drop.

Figure 5. USAFSAM mental fatigue scale.


How does this fit in the big picture?

Flight Surgeons will continue to trial caffeine Chew Pod on OP IMPACT personnel to collect more data to support RCAF FRMS implementa- tion. With the continued momentum of positive results, this PFCM may soon become further integrated for use in the RCAF. By addressing one of the many layers of FRMS defence, the Flight Surgeon community aims to provide an effective tool to mitigate the threats of fatigue.


  1. “AFO 8008-0 Fatigue Risk Management System for the Royal Canadian Air Force.” Royal Canadian Air Force. Accessed at on 5 Oct 2017.

  1. “Caffeine in Food.” Health Canada.
    Accessed at health-canada/services/food-nutrition/food- safety/food-additives/caffeine-foods/foods. html on 4 Oct 2017.
  2. Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. Accessed at https://www. PMHT0023062/ on 17 Oct 2017.
  3. “Tips for Better Sleep.” Centers for Disease Control and Prevention. Accessed at sleep_hygiene.html on 4 Oct 2017.
  4. Lerman, Steven E. et al. "Fatigue Risk Management in the Workplace." Journal of Occupational and Environmental Medicine 54.2 (2012): 231-58. Accessed at http://www. Policies_And_Position_Statements/ Fatigue%20Risk%20Management%20 in%20the%20Workplace.pdf on 4 Oct 2017.
  5. Flin, Rhona H., Paul O'Connor, and Margaret Crichton. “Safety at the Sharp End: A Guide to Non-Technical Skills.” Aldershot, England: Ashgate, 2008, pp 192-93.
  6. “Reduce Fatigue-related Accidents.” National Transportation Safety Board. Accessed at mwl1-2016.aspx on 4 Oct 2017.
  7. “Basics of Aviation Fatigue.” U.S. Department of Transportation Federal Aviation Administration. Accessed at https://www. Circular/AC%20120-100.pdf on 4 Oct 2017.
  8. “Chapter 3 – Fatigue Risk Management System.” Transport Canada. Accessed at publications/tp14576-3-fatigue-6098.htm on 4 Oct 2017.
  9. Samn, Sherwood W. and Perelli, Layne P. “Estimating Aircrew Fatigue: A Technique With Application to Airlift Operations.” USAF School of Aerospace Medicine, 1982.

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