Caffeine administration at night during extended wakefulness effectively mitigates performance impairment but not subjective assessments of fatigue and sleepiness

Abstract

The current study investigated the effects of repeated caffeine administration on performance and subjective reports of sleepiness and fatigue during 50h extended wakefulness. Twenty-four, non-smokers aged 22.5±2.9y (mean±SD) remained awake for two nights (50h) in a controlled laboratory environment. During this period, 200mg of caffeine or placebo gum was administered at 01:00, 03:00, 05:00 and 07:00 on both nights (total of 800mg/night). Neurobehavioral performance and subjective reports were assessed throughout the wake period. Caffeine improved performance compared to placebo, but did not affect overall ratings of subjective sleepiness and fatigue. Performance and sleepiness worsened with increasing time awake for both conditions. However, caffeine slowed performance impairments such that after 50h of wakefulness performance was better following caffeine administration compared to placebo. Caffeine also slowed the increase in subjective sleepiness and performance ratings, but only during the first night of wakefulness. After two nights of sleep deprivation, there was no difference in sleepiness ratings between the two conditions. These results demonstrate that strategic administration of caffeine effectively mitigates performance impairments associated with 50h wakefulness but does not improve overall subjective assessments of sleepiness, fatigue and performance. Results indicate that while performance impairment is alleviated, individuals may continue to report feelings of sleepiness. Individuals who use caffeine as a countermeasure in sustained operations may feel as though caffeine is not effective despite impairments in objective performance being largely mitigated.

Decreased salivary alpha-amylase levels are associated with performance deficits during sleep loss

“…Participants were recruited to take part in a study investigating the effects of caffeine gum administration on performance and sleepiness during 50 h of total sleep deprivation (TSD). Data pertaining to the scope of the larger study are published elsewhere (Johnson et al, 2016;Paech et al, 2016). Only data relating to the control condition (i.e.…”

“…Currently, self-assessment of sleepiness or performance during extended wakefulness is the most common method of monitoring performance and safety in the workplace (Christodoulou, 2012). However, inter-individual differences in the effects of sleep loss on performance (Van Dongen et al, 2004) and reports of discrepancies between subjective assessment of sleepiness and objective performance (Paech et al, 2016;Zhou et al, 2012), have led to the recent interest in non-invasive, objective, physiological monitoring of operator performance.…”

Methylxanthines in 100 Brazilian herbs and infusions: determination and consumption

“…Regarding the stimulant function of caffeine, it stimulates the central nervous system and cardiac activities (Seifert et al, 2011;Trabulo et al, 2011), increasing the physical anbd mental performance, improving the sense of humor and memory (Bizzotto et al, 2013;Malinauskas et al, 2007;Pohler, 2010). Paech et al (2016) administered caffeine to adults who were kept awake for 50 hours; the results showed that the individuals who received caffeine presented a lower reduction of performance when compared with the control group; however, they did not observe any reduction in the sensation of sleep and tiredness.…”

The impact of caffeine consumption during 50 hr of extended wakefulness on glucose metabolism, self‐reported hunger and mood state

“…Participants then began 50 hr of extended wake (day 1; 08:00 hours to day 3; 10:00 hours, <50 lux). Throughout the extended wake period, participants completed cognitive test batteries at regular intervals, results published elsewhere (Johnson et al., ; Paech, Banks et al., ; Pajcin et al., ). Meal tolerance tests were completed at breakfast on days 2–4.…”