Research published in Aerospace Medicine and Human Performance suggests that U.S. Army aircrew regularly use caffeine to cope with the demands of the job, amidst a lack of knowledge of positive dietary habits.
Caffeine is widely consumed across America, mostly in the form of cups of coffee but with energy drinks becoming increasingly fashionable. Study authors Asma S. Bukhari and team wanted to investigate the use of caffeine products among U.S. Army flight crew members, where circumstances of the job include reduced sleep and a high mental workload.
Bukhari and team surveyed 188 aviation crew members from the Combat Aviation Brigade at Fort Campbell, Kentucky. To obtain more detailed answers, a focus group session was also conducted among a smaller sample of 47 aircrew members. Most (94%) of participants served in combat units.
The survey results revealed a lack of sleep among the flight crew. On average, subjects reported getting 6.15 hours of sleep per night when deployed, although they reported needing 7.22 hours a night to feel well-rested. The authors note that the 6.15 hour average is much less than the recommended 8 hours for “optimal cognitive performance.” When participants were asked how many times they felt so tired that they fell asleep while flying, the average answer was 1.95 times.
Most (65%) of the aircrew members said they use some type of caffeine product daily, with energy drinks accounting for 30% of this caffeine intake. Around 55% of the sample drank energy drinks or energy shots at least weekly.
The focus group revealed insights into crew members’ day to day work lives. Common themes were unpredictable schedules that disrupted their sleeping habits, long work days, high degrees of responsibility for team member’s safety, and heightened stress.
Discussion concerning the use of energy drinks suggested it to be widely accepted among the military aviation community, despite uncertainty that such use was approved for by the Army. As the authors report, the focus group appeared to feel it was okay to use energy drinks as long as they were not abused, and that subjects “generally felt the benefit of commercial energy drinks outweighed the risks, especially when deployed.”
The focus group did voice a lack of knowledge concerning positive dietary habits and worry about the possibility of becoming addicted to energy drinks and experiencing withdrawal without them. “Flight crewmembers,” the authors say, “were concerned about exhaustion and ‘crashing’ after energy drink and caffeine use. They felt that even if personnel used energy drinks outside of the 12-h window prior to flight, they still might suffer from disrupted or insufficient pre-mission sleep as a result.”
As the researchers report, the main reason given for using energy drinks was for performance enhancement, suggesting aviation personnel were “using caffeine to cope, at least in part, with the adverse effects of sleep restriction, shift work, and highly variable work/rest schedules.”
Bukhari and team say that 60% of the focus group reported not having asked for approval from a flight surgeon before consuming energy drinks, which the researchers suggest may have to do with uncertainty regarding whether such caffeine products are permitted. The researchers conclude that aviation personnel would benefit from education on Army policies regarding the use of supplements as well as information regarding positive dietary choices.
The study, “Caffeine, Energy Beverage Consumption, Fitness, and Sleep in U.S. Army Aviation Personnel”, was authored by Asma S. Bukhari, John A. Caldwell, Adam J. DiChiara, Ellen P. Merrill, Alan O. Wright, Renee E. Cole, Adrienne Hatch-McChesney, Susan M. McGraw, and Harris R. Lieberman.
