How Dehydration Slows Down the Brain:

How Dehydration Slows Down the Brain

128, Environment, Exercise & Fitness, Men's Health, The Human Body, Women's Health

It’s hard to understate the importance of water to the body. One thing that might surprise you, however, is the impact that a lack of water can have on the human mind.

Heat and Exercise

According to a 2018 study from Georgia Tech University, even a small amount of dehydration can hinder our ability to complete and focus on specific tasks. Likewise, this same issue can negatively affect our control over our motor functions. The study appeared in the journal of July 2018 issue of Medicine & Science in Sports & Exercise.

For their work, the authors relied on a bevy of previous scientific reports to examine this issue. Over thirty previous such studies were reviewed, allowing the team to review data from over 400 individuals. Each participant was asked to complete both mental and physical cognitive tests after becoming dehydrated through one of the following means:

Exercise in Heat
Exercise
Heat stress with no exercise
Fluid restriction

Once the subjects reached a water deficit greater than 2 percent of their body mass, they experienced a temporary yet noticeable decline in cognitive functionality. The report’s conclusion section found that “despite variability among studies, [dehydration] impairs cognitive performance, particularly for tasks involving attention, executive function, and motor coordination when water deficits exceed 2% body mass loss.

Drink Up!

In response to a follow-up email from The Washington Times, lead researcher Matthew T. Wittbrodt noted that the human body can become 1 to 2 percent dehydrated after failing to consume any liquids for a 12 hour period. By the same token, humans can suffer one percent dehydration after completing an hour of moderate level physical activity.

In his correspondence with the Times, Wittbrodt further noted that feelings of thirst tend to go hand in hand with dehydration. “A distinct sensation of thirst appears as body water losses approach 2% body mass loss. Thus, if someone feels thirsty, they are likely within the range of dehydration we found results in cognitive impairment.”