Associated Professional Sleep Societies conducted a study recently which shows that after just three nights of bad sleep, caffeine stopped boosting alertness, performance, and mood. Researchers mimicked a work week where 48 adults were given 10 hours of sleep in the first week, and this was cut down to 5 hours in the following week. Caffeinated (200 milligrams) or placebo tablets were distributed randomly twice a day, and a check was kept on the reaction time, mood and sleepiness. Participants who chewed caffeinated gums showed higher levels of sleepiness and irritation and lower levels of performance, as compared to the participants who took the placebo, when their sleep time was restricted to 5 hours.

The Verdict – Your body will need higher levels of caffeine to keep up with your sleepless nights, and three days is the trial that a human body can usually go through. Sleep debt, which is the difference between the amount of sleep you need and the amount that you let yourself have, is bound to catch up. Four cups of coffee a day may help you get through it, but your body’s need for rest cannot be overridden by the intake of chemicals, the study says. 

A possible reason why this happens could be the adenosine hypothesis, a mechanism which shows that as the sleep debt increases, the thinking capacity goes down and so does the neurotransmitter adenosine and/or its receptors in the brain. At first, caffeine is able to block the effects of adenosine binding itself to its receptors. The elixir however fails to perform because with an increase in your sleep debt there is also an increase in adenosine. There’s only so much that coffee can do.

So if you think you will be faced with all-nighters, get yourself 10 hours of sleep for a few days in advance to counter the effects of sleep debt. That should help you get through. Because you will have to sleep it out in the end, there are no two ways about it.