Drink Up, Hydration & Water

If You’re Tired and Cranky a Lot, This Could Be the Reason


By Keri Glassman, MS, RD

Ask Keri: Are dehydration and fatigue related?

Keri Says: In fact, fatigue is one of the major effects of dehydration. If you’re not getting enough water, you’re not going to have enough energy to get through the day effectively (let alone to kill it at work, get in a rowing class, and make the kids a healthy dinner).

Of course, if you’re feeling tired way too often, there are many other things that could be the culprit. You may not be sleeping enough (that’s the obvious one!) or you could have a nutrient deficiency, to name just a couple of alternate reasons.

But evaluating how much water you’re drinking isn’t a bad place to start. Here’s why.

RELATED: How Much Water Do You Need to Drink Daily?

Dehydration and Fatigue: The Science

Nearly all of the body’s systems depend on water to function properly.

For example, water lubricates joints and regulates body temperature. More importantly in terms of energy levels, H2O is crucial for proper digestion (and you can’t be energetic without fuel!), helps your heart pump blood more effectively, and helps transport oxygen and other essential nutrients to your cells. It also affects your brain—about 70 to 80 percent of your brain tissue is water—and fatigue and mood are closely related.

RELATED: Should You Be Taking Nootropics for a Brain Boost?

dehydration and fatigue

While water is super important, you’re also constantly losing it, via breath, sweat, and urine. When you lose too much and don’t replace it, research shows you lose steam. In a pair of studies published in 2011 and 2012, researchers induced mild dehydration in small groups of men and women and then put them through testing. Both groups experienced fatigue as a result of dehydration. Interestingly, the women in the study experienced “degraded moods” and an inability to concentrate at higher levels than the men.

In other words, sorry ladies, dehydration could make you tired and cranky.

Dehydration and Fatigue: The Bottom Line

While the clinical trial evidence on hydration and fatigue mainly consists of small studies, the basic science is clear: your body needs water to function. So, whether you’re working out or working a desk job, you should pay close attention to staying well hydrated 24-7. After all, there are so many other things that can sap your energy—like stressful meetings and relationships—so you want to shore up your defenses in advance. And what’s easier than sipping from your water bottle while you type or tread?

(Photos: Shutterstock)


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