How long does the coffee

Coffee may seem elixir of life, when we do not get enough sleep. However, research has proven that he is not omnipotent. Sooner or later it will cease to work, and you still have to go to bed.

The action of coffee is not unlimited. The study, presented in 2016 at the Congress of American professional somnological communities Denver has proven that caffeine stops to increase our activity and improve mood after three nights lack of sleep ^[1].

"The findings also confirmed that sleep deficit - it is a real phenomenon," - says Tracy Doty (Tracy Doty), head of the research group of the Military Research Institute Walter Reed.

The more we do not get enough sleep, the less caffeine affects us.

A week before the start of the study 48 participants in the experiment were sleeping for ten hours a day. The next five days the subjects slept only five hours. Each participant twice a day, at 8 am and in the afternoon, were given either 200 milligrams of caffeine (the equivalent of two cups of strong coffee

At the beginning, participants who received the caffeine, showed significantly better results: they respond quicker and feel more energetic. But after three nights of sleep deprivation of their state equalized with members of the other group. They even get tired more and more annoyed than participants taking placebo.

Thus, the study confirms that the deficit sleep - the difference between the required and obtained bedtime - complicates our mental activity. Four cups of coffee a day may help at first, but soon the lack of sleep still will prevail.

Tracy Doughty believes that one of the possible reasons is the neurotransmitter adenosine. If we do not get enough sleep, the concentration of adenosine and its receptors in the brain increases. When adenosine binds to its receptor, we feel even more sleepy.

Caffeine is only a short time is able to block adenosine receptors, but as soon as the shortage of sleep increases the coffee no longer cope with the problem.

Thus, if you will be a heavy week, try a few days before to sleep at 10 o'clock. So you fill up your reserves of sleep and can last throughout the week.

1. D. C. Cooper, T. J. Doty, P. J. Quartana, K. M. Maguire, E. M. Bergman, S. K. Trach, C. J. So, R. H. Ratcliffe, J. E. Moon, V. F. Capaldi, T. J. Balkin.The Effects of Caffeine on Psychomotor Vigilance Task Performance During Sleep Restriction and Recovery.