Jet lag and shift work sleep disorder can result in sleepiness and increase the risk of mistakes or injury. Overall, it is suggested that caffeine may be an effective countermeasure to impairments associated with sleep loss2.
Shift work
Shift work sleep disorder is a circadian rhythm sleep disorder characterised by insomnia and excessive sleepiness, affecting people whose work hours are scheduled during the typical sleep period. Whilst specific research is limited, a systematic review suggests that caffeine may be effective at improving performance in people who work shifts, or in those who are suffering from jet lag10.
A 2021 systematic review also suggested that caffeinated energy drinks led to improvement in select driving performance variables and reaction time after prolonged night shifts among medical trainees. However, the authors suggested that more investigation is needed to identify interventions to help adapt to and recover from working shifts11.
A systematic review of seven empirical studies, including three randomised controlled trials, examined fatigue among military aviation pilots with irregular schedules and night shifts concluded that pharmacological interventions, including caffeine were the most effective short-term countermeasures, improve vigilance, reaction time, and performance during extended wakefulness. However, the authors cautioned that an over-reliance on stimulants is insufficient12.
Jet lag
Coffee consumption is associated with increased alertness, may help to manage feelings of sleepiness, and can be effective at improving performance in those who experience jet lag after a long haul flight crossing time zones13. One study suggests that sensible naps, combined with a moderate intake of caffeine during times of appropriate wakefulness and short-term use of sleeping aids, appear to be the most effective ways to maintain alertness and sleep in these situations13.
