Is Your Morning Cup of Coffee Making You Tired?

I admit, the minute my alarm goes off at 5:30 am each morning, my first thought is – time for coffee! (anyone else?) I love the flavor, the burst of energy, and most of all – my morning ritual of sipping it while slowly starting my day.

I’m not alone. More than 95% of adults living in the United States consume coffee.
The average consumption of caffeine was 120 mg per day in 1999. By 2010, the number grew to 165 mg per day. And, in 2017, the average intake was 190 mg per day (1).

Among all caffeine consumers, those in the 50 to 64 age group tend to take in the highest amount of caffeine. And, the top 10% highest amount of consumers take in an average of 380 mg per day (2).

Surprisingly, the #1 reason why Americans say they drink coffee is they like the taste, followed closely by to help wake up (3).

While coffee can indeed provide a burst of energy, it may also leave you feeling sluggish.

3 Reasons why coffee is making you feel tired

1. Coffee blocks the chemical Adenosine.

Adenosine is a chemical of your central nervous system, which helps regulate your sleep-wake cycle. During the day, your adenosine levels increase and eventually make you drowsy by bedtime. After you fall asleep, adenosine levels drop.

Caffeine in coffee blocks the brain’s adenosine receptors from receiving adenosine, but it doesn’t stop the actual production of adenosine or the ability to form additional adenosine receptors. This means that when the effects of caffeine wear off, there’s a buildup of adenosine wanting to bind to its receptors. This can lead to a drop in your energy and feeling tired.

2. Coffee is a diuretic.

Diuretics are cause increased urination, resulting in a loss of fluids. This can decrease your blood pressure, leaving you feeling sluggish. Additionally, when you’re dehydrated, cells in the body lose fluid volume. When this affects their normal function, it can also lead to feelings of sluggishness.
It’s natural to reach for another cup of coffee to get a quick boost to your energy, but this can start the cycle all over again.

3. You may feel sluggish because of what you add to your coffee.

If you like to add sugar to your coffee, you may have regular sugar “crashes” after drinking it. This added sugar may come in the form of whipped cream or shots of flavored syrup to your morning latte. Your body processes sugar much faster than caffeine. After sugar is used up by your body, you may experience an energy slump and this can happen within 90 minutes of consuming a high sugar coffee beverage.

So, before you down that venti white mocha with two espresso shots, three packets of Splenda, and an extra pump of vanilla, just remember that I warned you.

What is the Recommended max intake of caffeine/day?

The US Dietary Guidelines recommend a maximum intake of 400 mg/day for adults from all sources (4).  This includes coffee, tea, energy drinks, foods, and even workout supplements.

How much caffeine is in your drink?

Keep in mind that the actual caffeine content of a cup of coffee or tea can vary quite a bit. Factors such as processing and brewing time affect the caffeine level. So use these numbers as a guide.

Coffee drinks Size in oz. (mL) Caffeine (mg)
Brewed 8 (237) 125
Espresso 1 (30) 70
Brewed black 8 (237) 47
Brewed green 8 (237) 28
Cola 8 (237) 22
Energy drink 8 (237) 29
Energy shot 1 (30) 215

While you don’t need to give up your morning coffee, here’s 3 simple tips to help you feel less tired, and more energized through your day.

1. Avoid coffee-based drinks with sugary syrups and sugar.
2. Alternate one cup of coffee with one cup of water to avoid dehydration.
3. Drink tea, which contains a smaller amount of caffeine.

1. Caffeine intake and its sources: A review of national representative studies.

2. U.S. consumers’ reasons for drinking coffee 2017 | Statista


4. A Closer Look at Current Intakes and Recommended Shifts – 2015-2020 Dietary Guidelines |

5. Caffeine content for coffee, tea, soda and more.