Chapter 3: Caffeine Can Stay in Your System Longer Than You Think

Coffee is not the only source of caffeine.

Tea, energy drinks, cola, pre-workout products, chocolate beverages, and some medications can also contain caffeine. For people who are sensitive to it, consuming caffeine late in the day can interfere with sleep even when they do not immediately feel energized.

Caffeine works primarily by blocking adenosine receptors in the brain. Adenosine is one of the chemicals involved in the buildup of sleep pressure during the day.

Because caffeine can remain in the body for hours, drinking a caffeinated beverage close to bedtime may make it harder for some people to fall asleep or may reduce sleep duration.

The effect varies considerably from one person to another.

One individual might drink coffee after dinner and sleep normally. Another person may consume the same amount and remain awake much longer than expected.

Energy drinks deserve particular attention because some contain substantial amounts of caffeine along with added sugar and other stimulants.

People who already experience palpitations, anxiety, insomnia, or sensitivity to caffeine may want to be especially cautious about consuming highly caffeinated beverages late in the day.

And there is a common trap: someone may drink caffeine because they are tired from poor sleep, then consume more caffeine the following day, sleep poorly again, and repeat the cycle.

Instead of relying on increasingly late caffeine consumption, it may be more useful to examine the underlying reason for persistent fatigue.

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Chapter 4: Sugary Drinks Can Become an Unnoticed Nighttime Habit

The third category is sugary beverages.