Let’s get one thing straight, for those of you that know me I love my coffee. For me it’s like throwing gasoline on a small campfire to get me going in the morning.
But some people actually get MORE tired after a cup of coffee.
So can caffeine actually work in reverse and make you tired all the time?
Coffee can actually make us sleepier and more fatigued.
So we have to review how caffeine affects the body first. A quick overview for those taking notes.
Caffeine targets the central nervous system. It stimulates the release of a neurotransmitter called dopamine. And dopamine controls pleasurable sensations. Dopamine also bumps up your heart rate which gets more oxygen out into the muscles. This increase in heart rate can also stimulate stress hormones like cortisol and epinephrine (adrenaline) which can throw us into a “fight or flight” mode. This stress response drives us to feel more alert while boosting concentration and coordination and when used in small doses the caffeine can wake us up and help us feel energized.
But sometimes, caffeine can have an opposite effect, it can make us sleepy.
So how in the heck does it make you feel tired if it’s a stimulant?
Coffee Blocks Adenosine
Adenosine regulates your sleep & wake cycles. It binds to specific receptor sites in the brain and prepares your body for sleep. Caffeine blocks the receptor sites.
No sites for adenosine to bind = you’re not sleepy
The problem is that when you’re pounding coffee your body continues to release adenosine. So, when the coffee/caffeine wears off, you’ve got an excess of adenosine floating around in your system and as the blocked receptors clear off, it can lead to sleepiness.
Let’s face it, caffeine is a drug, and like a lot of drugs if you use it regularly your body gets accustomed to its effects and ultimately you have to take more to overcome what the body is used to.
Folks who drink coffee every day *raises hand* can build up a strong tolerance to caffeine. Your body will actually boost the number of adenosine (sleepy) receptors. If you keep blocking the ones you have your body will just work around your habits and create new ones.
If you start drinking less than your normal amount, you’ll experience caffeine withdrawals due to excess of adenosine receptors. It may feel like getting slammed by a wave of sleepiness. So if you’re cutting back to increase your sensitivity to caffeine, you may feel more tired as your body adjusts.
Sugar in that Coffee
Maybe it’s not the coffee at all (doubtful), maybe it’s the sugar you add.
If you take your coffee black like a normal person, skip this part.
When you consume more sugar/carbs that your body is accustomed to, your body dumps an excess amount of insulin to counteract it. When you have an excess of insulin floating around in your system your blood sugar drops which causes tiredness.
Coffee is a Diuretic
It makes you pee!
Urination drives fluid loss which drives dehydration which makes you feel tired.
However, Harvard Medical threw out the theory that the water in the coffee offsets the diuretic effect resulting in a net zero but still, drink more water than coffee during the day.
Coffee Induced Stress
Caffeine is a stimulant and it affects hormones like cortisol and adrenaline. When used intermittently, these hormones can make us feel energized but as they wear off we may feel fatigued and drowsy.
Constant caffeine use results in higher highs (caffeine buzz) but also begins to result in lower lows (chronic tiredness).