Most of us are reliant on our morning coffee to wake us up and get us ready for the day ahead, but is it really working? The American Academy of Sleep Medicine investigated just how effective our daily cup of Joe is at keeping us alert and awake after multiple low-sleep nights.
48 participants limited their sleep to five hours over the course of five nights. Half of the participants were given 400mg of caffeine (the equivalent of four cups of coffee) and the other half was given a placebo every morning during the five days.
After receiving their pills, the participants underwent a variety of tests to look at their mood, sleepiness, vigilance, and cognitive ability.
During the first two days, the participants with the caffeine supplement overwhelmingly performed better than the control group. However, three days of not getting enough sleep later, the caffeine supplement had no effect on boosting the performance of the participants, and the control group was performing just as well as the test group was.
"These results are important, because caffeine is a stimulant widely used to counteract performance decline following periods of restricted sleep,” said lead author Tracy Jill Doty, PhD of the Walter Reed Army Institute of Research. “The data from this study suggests that the same effective daily dose of caffeine is not sufficient to prevent performance decline over multiple days of restricted sleep."
In short, coffee can be a quick fix for one day of less sleep, but it is not a longterm solution.