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Caffeine CEMS Article

Posted by Jason on September 22, 2010


Caffeine is a stimulant drug. For caffeine to serve as an alertness boost, it must be consumed at low levels and only when needed.


High doses of caffeine can result in increased anxiety, lack of concentration and digestive disorders. Some people develop a greater sensitivity to caffeine and experience these symptoms even at low doses.

Frequent consumption of caffeine can result in addiction.

Common sources of caffeine include: coffee, tea, chocolate, soft drinks and medications (over-the-counter and prescription).

Endurance Tips

Crewmembers addicted to caffeine should discontinue use and undergo withdrawal. Withdrawal can last two weeks and can include headaches, attention deficit, endurance degradation and lack of motivation. Sleep patterns should begin to improve within this period, but energetic alertness after awakening may not be restored until the withdrawal process is complete.

If withdrawal is not desirable, reducing exposure to caffeine to one beverage (cup of coffee, bottle of soda, chocolate drink) per day can be a good compromise.

If caffeine is needed to maintain alertness during daytime hours, a physician should be consulted to evaluate the possibility of a sleep disorder.

Crewmembers taking over-the-counter or prescription medications that contain caffeine (or another stimulant) should closely follow the dosage instructions.

Caffeine should be used as a stimulant to boost alertness only when necessary and should be avoided altogether within four hours of bedtime.

Source: Crew Endurance Management Practices
A Guide for Maritime Operations - United States Coast Guard