June 15, 2016 · Team HG
The 2016 American study ‘SLEEP’ showed that caffeine consumption is no longer effective after a few nights of little sleep. Many people drink coffee to counteract impaired performance caused by lack of sleep, but it now appears that this no longer has the same effect after a few nights.
During the research ‘SLEEPby the Walter Reed Army Institute of Research In a study from the United States (2016), 48 volunteers spent nine days in a sleep lab. On the first night, they were given the opportunity to sleep as long as they wanted; for the following five nights, the subjects were woken up at 5:00 AM and taken out of bed. For the subsequent three nights, the same people slept for eight hours to recover from the short nights.
Caffeine
During the short nights, some of the participants received 200 milligrams of caffeine twice a day, while the others received a placebo. Caffeine is a substance that, in small amounts, improves concentration and performance and dispels fatigue. Naturally, this substance is found in coffee and tea, but also in certain soft drinks and chocolate.
Effects
The participants performed multiple cognitive tests; aspects such as alertness, mood, sleepiness, and the ability to stay awake were measured regularly.
During the study, it was found that in subjects who had slept only five hours for three nights, caffeine no longer had the same (positive) effect on alertness as before. Caffeine is often consumed with the idea of counteracting impaired performance associated with lack of sleep, but it now appears that after several days, caffeine is no longer effective in this regard.
Caffeine also had negative effects over time: during the first short nights, those who used caffeine were happier, but later these individuals were actually more irritable than the placebo users. Adverse effects of excessive caffeine use include symptoms such as restlessness, anxiety, sleep problems, or headaches. What constitutes "too much" varies greatly from person to person.
