No This Won’t Dehydrate You

No This Won’t Dehydrate You


One of the persistent myths in the world is that coffee dehydrates you.

The belief that caffeinated drinks such as coffee could cause dehydration is based on a 1928 study that demonstrated caffeine’s diuretic effect.

Back then there was not a standard measure to determine hydration, but it was based on how often people would go to the bathroom after taking caffeine.

Since then, only two studies have tried to see if there was enough evidence to support that belief now that our ability to measure hydration has gotten better.

Yet despite the lack of evidence everyone’s doctor will tell them if you have a cold stay away from caffeinated beverages.

It wasn’t until 2014 when researchers at the University of Birmingham England finally checked to see if this was true.

They wanted to see if regular coffee drinkers were, in fact, dehydrating themselves.

In other words, is your mother, right?

Is water the only drink you can use to get hydrated?

No, mom is wrong.

The study looked at 50 men and asked half to drink water, the other half coffee.

Neither group was ever dehydrated.

They even switched mid-way in the study and the results stayed the same.

Strangely many public health services still keep telling people to drink a cup of water following coffee or tea to make up for the “dehydration.”

This recommendation is based on a 2005 study which showed caffeinated beverages do not cause dehydration, yet the author suggested abstaining from caffeine before working out without any data to suggest this was necessary.

Coffee and Working Out

Many people use “pre-workout” formulas for an extra energy boost during their workouts. But many people have realized most of these formulas are mostly sugar and caffeine.

Some have figured out that you can get the same effect on their energy level by drinking coffee which is usually significantly cheaper than most pre-workout formulas.

The Birmingham study is significant because it shows that coffee also hydrates you.

So, you are getting a great deal of bang for the buck.

But where it gets interesting is drinking coffee post workout.

The American Physiological Society published a study in 2008 where they took athletes that depleted their glycogen stores by having them not eat after a workout and then worked them out again the next day in a fasted state.

Half of the athletes got a carbohydrate drink and the others got the same drink with caffeine.  The result was interesting.

The athlete’s muscles absorbed the carbs and nutrients into the muscles much faster with the caffeine.

Again, you are replenishing fluids, not dehydrating yourself, but you are also helping your muscles repair more quickly.

Some ideas take a while to get out to the public mind.  For instance, you “can’t swim until 30 minutes after you eat” refuses to go away.

So, if you are sick, working out or just enjoying your life, coffee or a caffeinated beverage will not dehydrate you.

You do not need to drink water to make up for fluid loss after drinking a cup of coffee.

All fluids count toward staying hydrated no matter what form or amount of caffeine is involved.

Bonus tip – My post workout drink

I make CBD infused coffee before I go to the gym and when I get home I take the cold coffee and mixed it with protein powder.

My post workout drink has:

  • 15 grams of protein
  • CBD as an anti-inflammatory
  • Caffeine to help with recovery
  • Hydration

Essentially everything you need in one beverage to help you recover quickly.

You can also add salt and other electrolytes to this post-workout beverage, which you might want to do after you read this article on the importance of salt in the diet and how the recommendations of the federal government seems to be incorrect:  (Click here for story on salt and why you probably are not getting enough)