BACKGROUND: Caffeine-containing products and dietary supplements are widely used by military populations, but little is known about their use by aviation personnel. This study assessed self-reported sleep, fitness, work-schedules, and caffeine/energy drink use.METHODS: A standardized survey was conducted in person by study personnel using tablet computers. A total of 188 aircrew members from the Combat Aviation Brigade at Fort Campbell, KY, participated in the survey. Focus groups were conducted with a subset of 47 subjects.RESULTS: The majority of subjects reported their physical fitness, health, and diets were good. They reported sleeping about 6 h per day and stated they needed additional sleep to feel fully rested. Their caffeine consumption averaged 346 ± 23 mg · d-1 with most derived from coffee (139 ± 12 mg · d-1) and energy drinks (110 ± 13 mg · d-1). About half (55%) of participants used energy drinks at least once per week and they consumed greater amounts of caffeine than nonusers. Focus group data indicated crewmembers primarily consumed energy drinks to enhance performance degraded by variations in work schedules and lack of sufficient sleep. Participants expressed a desire for additional education on diets and energy drinks as well as on aeromedical policies governing energy drink and supplement use.CONCLUSIONS: Caffeinated products, including coffee and energy drinks, are routinely used by Army aircrews to increase alertness. Aircrew personnel consider them generally safe, but would like to receive education about these beverages, other dietary issues, and Army policies governing their use in aircrew.Bukhari AS, Caldwell JA, DiChiara AJ, Merrill EP, Wright AO, Cole RE, Hatch-McChesney A, McGraw SM, Lieberman HR. Caffeine, energy beverage consumption, fitness, and sleep in U.S. Army aviation personnel. Aerosp Med Hum Perform. 2020; 91(8):641-650.