According to renowned sleep scientist, Dr. Matthew Walker, “Caffeine temporarily blocks brain signals from adenosine, a sleep chemical, which nonetheless continues to accumulate.”
Adenosine naturally builds up throughout the day. It creates a "sleep pressure" that gradually makes us more tired as we approach the evening. Caffeine blocks this natural process from happening.
This can be especially damaging to your sleep if you are regularly drinking caffeine in the afternoon.
Even if you can still fall asleep while under the influence of caffeine, your sleep quality is suffering.
The amount of deep sleep you get with caffeine in your system can decrease up to 30%. This type of consistently degraded sleep can age your body 10-12 years.
Additionally, you’ll keep requiring more caffeine, or other “uppers” in the morning to help your body feel alert enough to make up for the poor sleep.
We’re going to start avoiding caffeine (and other stimulants) in the afternoon.
Going forward, refrain from coffee, chocolate, nicotine, tea, and caffeinated sodas in the afternoon.
Specifically, you want to stop drinking caffeine for at least 10 hours before your normal bedtime.