Researchers claim that drinking a cup of coffee before a short power nap increases the impact of the caffeine on the brain.
When you consume coffee, the caffeine is absorbed via the small intestine and passes into your bloodstream. This is when it crosses into the brain and locks into receptors that are usually filled by a molecule, called adenosine, which is similarly shaped. This molecule is what promotes natural tiredness. Once it binds to receptors, it slows down nerve cell activity, which promotes drowsiness.
However, when caffeine locks onto the receptors, it speeds up the nerve cells. It takes around 20 minutes for this process from the point of consumption of the coffee to feeling more alert.
According to Vox the idea behind taking a coffee nap is that it during sleep adenosine is naturally cleared from the brain. This implies that taking a 20-minute nap should reduce the levels of adenosine in time for the caffeine to start its job.
Although scientists have not seen this happen in real-time, a number of studies in Japan and the UK have been done to view the implications of it.
Researchers based at Loughborough University discovered that when tired participants took a 15-minute coffee nap, they made fewer mistakes in a driving simulator, even if they had experienced problems falling asleep.
Another study indicated that coffee naps aid in going for longer periods without proper sleep.
One of these experiments involved 24 young males who were asked to go without proper sleep for a 24-hour period and were only allowed short naps. Of these, the half who took coffee naps showed better performance than the other half who was offered a placebo prior to their naps.
Image Credit: KuniakiIGARASHI