Coffee is the most popular beverage in the world. Over 450 million cups of coffee are consumed in America every single day. Most people turn to coffee as a drink to help wake up and feel energized. But some unlucky coffee-lovers are scratching their heads and wondering, ‘why does coffee make me sleepy?’.
It’s not actually the coffee that’s to blame. It’s the impact that caffeine has on your body and sleep wake cycle that makes you feel tired after just one or more cups.
Keep reading to unravel the reason why coffee can make you tired, and discover how you can use caffeine to gain more energy when you really need it.
3 reasons coffee is making you tired
The effects of caffeine impact people in many different ways. Some coffee drinkers can lug cup after cup without any adverse effects. Others have a more unpredictable relationship with coffee.
Here are some of the most common reasons coffee leads to excess fatigue, disrupting your sleep cycle in the process:
1. It can lead to a sugar crash
Are you loading your cup of coffee with spoonfuls of sugar, full fat milk, whipped cream and caramel? If the answer is yes, then you might have found the reason that you feel sleepy.
Excessive sugar in your coffee can counter the energizing effects of caffeine. Similar to energy drinks, and soda, when your coffee has too much sugar you can experience that dreadful feeling of a sugar rush and crash.
When you have too much sugar in your system, your body reacts by producing more insulin to help offset the increased glucose levels in the blood. Insulin plays a crucial role in controlling blood sugar levels by sending signals to the liver and other cells in the body to take in glucose from blood.
As the body produces more insulin, blood sugar levels can consequently drop causing a sudden drop in energy levels which can lead to bouts of fatigue and sleepiness. It’s not just coffee - other beverages or snacks loaded with sugar can also result in fatigue.
The solution? Reduce your sugar intake in your coffee. This includes artificial sweeteners such as whipped creams flavors. If you feel you can’t drink coffee without a little sweetness you can try a substitute of excess refined sugar for healthier sugar alternatives such as stevia, agave nectar, or maple syrup.
2. Adenosine receptors are getting blocked
Adenosine is a neurotransmitter that promotes sleep. After your ingest coffee, it travels through your bloodstream to different parts of your body. When caffeine enters the brain, it competes with adenosine to create a greater sense of alertness and wakefulness. This process is how caffeine can suddenly jolt you with energy.
Caffeine latches and blocks adenosine receptors, stopping the brain from processing these sleep-inducing molecules. After a few cups of joe throughout the day, adenosine builds up and once the caffeine metabolizes in your body, you can end up feeling more fatigued.
The accumulation of excess adenosine can often last until the next morning. People who consume large columns of caffeine each day and wake up groggy are likely such in a cycle of adenosine buildup.
Too much caffeine over a prolonged period of time can impact the sleep cycle and some may feel they don’t get the same caffeine boost they used to. Drinking too much coffee can therefore actually damage your baseline energy levels, causing an overreliance, which is why some people get addicted to caffeine.
The solution? Take note of how many times coffee makes you feel sleepy. If you notice it’s a daily thing, then this is a sign that you may need to work on improving your sleep cycle. It can help to ensure you have the most comfortable mattress and bedroom set up to support healthy sleep habits.
Limit your coffee intake and try to eliminate all caffeine after 3pm to improve your sleep cycle and flush adenosine out of your system.
3. Coffee is a diuretic and can cause dehydration
Have you ever consumed caffeine and felt the need to go to the toilet more times than normal? There’s a simple reason for this - coffee is actually a substance that makes you more likely to pass urine more frequently, also known as a ‘diuretic’.
The more frequently you pee, the more dehydrated you’re likely to become, which can result in heightened fatigue. When the cells in your body lose fluid, their function gets compromised, which is what you’re feeling when you experience lethargy after a coffee.
Coffee is also known to cause something known as ‘vasoconstriction’. This means certain blood vessels in your body are likely to constrict, which can in turn alter blood flow to different parts of your body. This is another reason you’re likely experiencing fatigue after drinking your regular cup.
The solution? Hydrating yourself adequately is going to prevent fatigue and sluggishness in the long-run, especially if you’re a big coffee drinker. Most sleep experts recommend men drink fifteen cups (or 3.7 litres) of water a day, while women only need eleven cups (which is 2.7 liters).
How to cut down on coffee gently
Curious to see what your sleep cycle and energy levels look like without coffee? Instead of going cold-turkey, try cutting out coffee gradually to minimize the ill effects of caffeine withdrawal.
One of the most common reasons most people struggle to quit drinking coffee is because the withdrawal symptoms are harsh. Not only do you (ironically) experience drowsiness after you quit drinking coffee, but you can also expect to experience irritability, nausea, headaches and poor focus without it.
Withdrawal tends to set in anywhere between twelve to twenty-four hours after you’ve had your last cup. Depending on how often you drink coffee regularly, your symptoms can last for a few days and up to a couple of a weeks.
Cutting down on coffee more gently can help you ease your way out of relying on it for energy. Try to reduce your consumption by a few cups each week and start supplementing your routine with less-caffeinated, herbal options.
The key is to replace your coffee habit with something equally delicious you can look forward to, whether this is a soothing cup of herbal tea, or an energizing snack.
Don’t want to quit coffee? No problem. Keep your intake under two cups a day, and try not to mix in any sugars or syrups when you do have yours. This can help keep you focused without the energy crash.
Frequently Asked Questions
Here are some quick answers to common questions about drinking coffee on a regular basis, and its direct impact on energy and sleep.
How many calories does coffee contain?
Plain coffee brewed from espresso beans has almost no calories, but that changes when you add milk, sugar, cream, or any flavorings to your drink. While a plain black coffee is just two calories, a flavored latte can be as much as 134 calories per 8 ounces.
How much caffeine is in coffee?
A cup of brewed coffee contains anywhere between 70 to 140 milligrams of caffeine. Instant coffee tends to have a little less, estimated between 30 to 90 milligrams depending on the brand you prefer.
How much caffeine can I have in a day?
Most experts agree that 400 milligrams of coffee a day is a safe amount to consume for the average adult. This is equivalent to four cups of brewed coffee a day.
Since the amount of caffeine varies depending on the type of coffee you’re drinking, be sure to check and ensure you aren’t going over your limit.
What should I do if coffee makes me sleepy?
If you’re sensitive to the amount of caffeine in coffee, it’s important you try and reduce the amount you drink gradually. Don’t worry - you don’t have to give coffee up completely!
You can still enjoy the occasional cup, and gain all the benefits of properly regulated sleep and energy while you’re at it.
If coffee makes me sleepy, are there alternate ways to boost energy?
Thankfully, you don’t have to rely solely on caffeine to give yourself an energy boost in the middle of the day. Herbal, non-caffeinated beverages such as peppermint or ginger tea can be an invigorating way to jumpstart your mornings.
You might also want to try something with naturally less caffeine in it - a cup of black tea has half as much caffeine as coffee does, but can be just as effective in boosting focus. Finally, certain snacks can also be helpful with increasing energy, such as bananas or apples.
If you’ve ever wondered in the past ‘why does coffee make me sleepy’, you should now have a better understanding of some of the underlying causes to your problem. Luckily, you’re far from alone, and this doesn’t have to be a permanent issue. With the right changes, you’ll be back to sleeping well and having healthy releases of energy throughout your day.
Your Turn...
Does coffee make you sleepy? Share your thoughts in the comments.
Disclaimer. We love sleep and we want you to get the best sleep possible. But we do not provide medical advice. This blog is intended for informational purposes only. It is not a substitute for professional medical info, diagnosis, or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on our blog.
- Award-winning comfort.
- Lifetime warranty.
- 101-night sleep trial.
- Free shipping and returns.
- 100% made in USA.
Written by Teresa Francis, Certified Sleep Science Coach
Teresa Francis is a Certified Sleep Science Coach and full-time writer focused on well-being and sleep health. She’s written on a variety of topics, from what’s trending in bedroom decor to the way lifestyle influences sleep. Some of the subject areas she covers for Puffy include the best foods for better sleep, how new parents can catch up on rest, and the best way to become a morning person. Teresa has a Master’s Degree in Literature, and has always believed in the power of a good bedtime story.