If you’ve ever run on little or no sleep for nights on end and you rely on caffeine to keep you alert and going during the day, you might get to a point where you feel it isn’t helping anymore.
A new study from the American Academy of Sleep Medicine, supported by the US Department of Defense Military Operational Medicine Research Program, has found that your coffee is not as beneficial as you might think for sleep deprivation. While might help you perk up after two late nights where you’ve burned the midnight oil, after that you can forget about it. It turns out that long-term, coffee really isn’t the thing that you need to stay awake and alert after a bad night of sleep
The study looked at forty-eight participants who had just five hours of sleep for five consecutive nights. Some were given a 200 mg jolt of caffeine twice during the day, while the others received a placebo instead (lucky them). The participants were given a battery of cognitive tests every hour they were awake, and a test of their wakefulness was done six times a day.
What researchers found was those who were caffeinated performed better on the first and second days than those who received a placebo.
However by the third night the benefits of the caffeine were definitely gone, and participants were performing at the same level regardless of whether they had been given the caffeine or not.
The lead author of the study, Tracy Jill Doty, PhD said: “We were particularly surprised that the performance advantage conferred by two daily 200 mg doses of caffeine was lost after three nights of sleep restriction.
“These results are important, because caffeine is a stimulant widely used to counteract performance decline following periods of restricted sleep.
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.”
Of course there are a few issues with this study. For one the sample size was relatively small, so there’s no way to tell what data might be gleaned from a larger group of people undergoing the same experiment. Along with that researchers only tested the same amount of caffeine every day, so we don’t know if having more caffeine on the third day might have kept the caffeine group more alert than the placebo group.
Those things aside, this research shows more than ever how important sleep is and that, for now anyway, there really is no alternative for getting at least a solid few hours of sleep every night. Adults should aim for about 8 hours for maximum health and wellbeing, but parents will likely find themselves operating on much less. We suggest that you do better than 5 hours, in any case!
And, even though coffee might not perk you up as much after the third day, according to science, we’ll probably keep on drinking it!