Not Drinking Enough Water May Be Worse for You Than You Think


Not Drinking Enough Water May Be Worse for You Than You Think

Your body is between 55% and 60% water. Men are at the high end of the range since they have more muscle and less body fat and fat tissue holds less water. Women, because they have more body fat, are around 55% water. Despite these small differences, more than half of the composition of your body is water, and you’re constantly losing water through your sweat and urine. That water needs to be replaced for you to stay healthy and feel your best.

Just HOW important is drinking enough water to replenish the water you lose? According to a recent study, even mild dehydration has an unexpected consequence – it adversely impacts the function of your blood vessels. Specifically, dehydration impedes endothelial function, the way in which blood vessels open and close. Under healthy circumstances, your blood vessels are flexible and open wide to allow blood and oxygen to be delivered to tissues.

Drinking Enough Water: Mild Dehydration is Bad for Your Blood Vessels

Based on this study, when you’re dehydrated, your blood vessels stiffen, making it harder for blood to flow through them. This is called endothelial dysfunction. As the researchers in this study point out the degree of blood vessels stiffening you get from mild dehydration is similar to what you get when you smoke a cigarette – and we know how bad THAT is for you. To make matters worse, poor endothelial function, from any cause, is linked with health problems like cardiovascular disease and stroke. In addition, stiff blood vessels cause your blood pressure to rise.

Here’s the surprising part. Being as little as 2% dehydrated can lead to endothelial dysfunction. At this level of dehydration, you wouldn’t have obvious symptoms. You would just feel a bit thirsty. That’s why it’s important to drink even when you aren’t thirsty. So, even a mild degree of dehydration, as little as 2%, isn’t healthy for your heart or blood vessels.

Drinking Enough Water: Mild Dehydration and Exercise

If you exercise, it’s easy to get mildly dehydrated without being aware of it, especially in the summer. If you exercise while dehydrated, the water loss causes your blood to thicken. Because your blood is thicker and harder to move through your blood vessels, your heart rate increases. This creates additional stress on your heart and makes physical exertion feel harder. It also leads to a reduction in exercise performance. In fact, you begin to notice a reduction in exercise performance after being about 2% dehydrated, around the point where you begin to feel thirsty.

The lesson to be learned? Everyone, regardless of activity, needs to drink enough water to avoid endothelial dysfunction but dehydration is much more common in active people who don’t drink enough water due to the sweat factor.

Drinking Enough Water: Other Problems Linked with Mild Dehydration

Mild dehydration can sneak up on you. You get busy and forget to drink enough water. Before you know it, you start to feel tired and lack motivation and wonder what’s wrong. It may be that your body is screaming out for fluid. Research shows mild dehydration can cause a person to feel fatigued and even a bit gloomy. You may also have problems concentrating and focusing.

Some people have dehydration symptoms and don’t know why they feel poorly. Older people, children, and anyone with diabetes are even more susceptible to dehydration. Plus, taking certain medications, like diuretics, heart medications, and some blood pressure medications, can increase fluid loss and lead to dehydration.

Drinking Enough Water: Water for Weight Control

There’s another reason to make friends with your water bottle. A study involving almost 10,000 young and middle-aged results showed that drinking more water and eating foods, like fruits and vegetables, with high water content helps with weight control.  Although not every study looking at water intake and weight control shows benefits, this study is unique in that it didn’t just measure how much water the participants drank but the specific gravity of their urine, how dilute or concentrated their urine was. This is a better measure of how much total fluid they were taking in from beverages and food.

The idea that drinking water might help with appetite control isn’t surprising. When you drink fluids or eat foods that have a high water content, your stomach expands. This sends a feedback message to the brain to turn off your appetite. Plus, foods that contain a lot of water are lower in calories, so it’s a win-win situation. In addition, it’s easy to mistake thirst for hunger and eat something when you really need to drink water instead. Next time you’re hungry, try drinking a glass of water before eating something. You may find that the water took care of your hunger. If not, try a crunchy piece of fruit with high water content.

How to Know if You’re Drinking Enough Water

Since it’s easy to mistake mild dehydration for simply feeling tired, how do you know when you’re not drinking enough? The best indicator is the color of your urine. If your urine is clear or pale yellow, you’re probably drinking enough fluids and can relax. If it’s dark yellow or brown, you’ve got some catching up to do.

Water versus Other Fluids

You might wonder whether tea or coffee is an acceptable substitute for water. Although research shows that caffeinated beverages like these are still hydrating, despite the caffeine, water is a better option. If you like drinking fluids with flavor, make your own fruit-infused water. Simply add your favorite herbs and fruit slices to a glass jar filled with water. Place it in the fridge for a few hours to let the flavors infuse into the water.

Come up with your own tasty combos of fruit and herbs. Herbs to try include basil, mint, rosemary, parsley, fresh ginger, or thyme. For fruits, you can choose from apples, pears, citrus, melon, berries, or your favorite tropical fruits. Try veggies too such as cucumbers or celery. Have fun experimenting with different combinations! You can have a different flavor of water to sip every day.

The Bottom Line

Now, you know another reason to drink more water. Mild dehydration that would hardly be noticeable can cause your blood vessels to misbehave. If you exercise, it can negatively impact your performance and it can make you feel tired and unmotivated. Carry along a stainless steel water bottle filled with the universal beverage and sip it frequently.



IDEA Health and Fitness. “Two Studies Underscore the Link Between Hydration and Health”

William Adams, et. al., “The Influence of Body Mass Loss on Changes in Heart Rate During Exercise in the Heat: A Systematic Review,” DOI: 10.1519/JSC.0000000000000501

Eur J Nutr. 2016 Feb 10. “The effect of hypohydration on endothelial function in young healthy adults.”

WebMD. “Even Mild Dehydration May Cause Emotional, Physical Problems”

CNN. “The new secret to losing weight? Water”

Ann Fam Med July/August 2016 vol. 14 no. 4 320-324.


Related Articles By Cathe:

If You Drink More Water, Will You Consume Fewer Calories?

6 Signs You’re Not Drinking Enough Water

How Hydration Affects Strength-Training Performance

Benefits of Drinking More Water and Tips for Making Sure You Do

Weight Training: Does Hydration Affect How Strong You Are?

What Role Does Hydration Play in Boosting Muscle Hypertrophy?

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