How Caffeine Works

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And so here we'll look at how caffeine
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works. So how does caffeine work? So
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what caffeine does is it blocks the
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action of a molecule in the brain called
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adenosine. And adenosine is responsible
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for making us feel sleepy. It's
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associated with what's called sleep
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inertia or essentially the drive to fall
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asleep. And when we consume caffeine
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about 30 to 60 minutes after consuming
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it, we see its increase uh in the blood
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and that increase begins to block the
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effects of adenosine which usually make
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us sleepy. And this effect lasts about 4
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to 6 hours.
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And this is where we get into really
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learning about why more caffeine doesn't
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necessarily mean more energy. And the
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reason for this is because once we
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consume enough caffeine to block all of
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the action of adenosine or that sleep
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molecule in the brain, then really
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consuming more caffeine isn't
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necessarily blocking more adenosine. So
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we're not necessarily getting more
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effects from it. And studies actually
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show that a more modest dose of
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caffeine, something like 150 milligrams,
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which is about a cup of coffee, provides
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most of the measurable alertness
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benefits, uh, with really little
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additional uh, benefits and alertness
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for more caffeine consumed.
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So the core point here really is that
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it's the timing, not necessarily the
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quantity of caffeine that is driving our
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performance benefit.