Why Your Afternoon Coffee Habit Is Ruining Your Sleep Quality
A new Australian study reveals that drinking afternoon coffee can severely impair sleep quality. Experts recommend finishing your last cup at least 8.8 hours before bedtime.
Many of us know the feeling: it is only two or three in the afternoon, energy levels begin to plummet, and we immediately reach for another cup of coffee or an energy drink. After all, the caffeine will wear off in an hour or two, right? It turns out not quite. Recent studies indicate that the time we drink our last cup of coffee of the day has a much greater significance than commonly thought, and that the habit of drinking coffee in the afternoon can severely impair sleep quality.
When Should You Really Stop Drinking Coffee?
A new study conducted in Australia, which reviewed 24 different studies on the subject, found that to avoid sleep disruption, one should finish their last cup of coffee at least 8.8 hours before bedtime. For example, someone who goes to sleep at 22:00 would need to finish their final coffee around 13:12.
"Consuming caffeine too close to bedtime can shorten total sleep time by about 45 minutes on average, prolong the time it takes to fall asleep by about 9 minutes, and add about 12 minutes of wakefulness during the night."
Pre-Workout Supplements and Caffeine
What about pre-workout supplements? Here the recommendation is even stricter. Because they contain double the amount of caffeine found in a regular cup of coffee, the study suggests consuming them at least 13.2 hours before sleep.
Why Caffeine Stays in the Body So Long
During the day, the body produces a natural substance called adenosine, the accumulation of which in the brain contributes to fatigue and helps us fall asleep. Caffeine, on the other hand, binds to the receptors where adenosine should attach and blocks them. Thus, we feel more alert, even when the body is signaling that it is time to rest.
However, caffeine does not disappear the moment we finish drinking. The body requires many hours to break it down, and in some cases, half of the caffeine remains in the system after more than nine hours. Therefore, even a cup consumed hours before bedtime can affect the night. Black tea, which contains a relatively small amount of caffeine, is an exception and was not found to impair sleep quality when consumed closer to bedtime.
