Cranky and tired? A glass of water could help

Kathleen Blanchard's picture
Mild dehydration alters mood and function.
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If you lose even 1.5% of your body fluid it might make you cranky, mentally foggy and tired, finds a new study. According to researchers at the University of Connecticut's Human Performance Laboratory, even mild dehydration that can occur anytime can alter a person’s mood and mental function.

The scientists conducted two studies showing that even at rest the effects of mild dehydration affects mood. Signs of thirst appear after a person is already 1 to 2% dehydrated.

Lawrence E. Armstrong, one of the studies' lead scientists and a professor of physiology in UConn's Department of Kinesiology in the Neag School of Education said in a media release,” Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer as it is for marathon runners, who can lose up to 8 percent of their body weight as water when they compete."

The researchers studied young men and women. Men in the study had an average age of 20, and the women were approximately 23-years of age. All of the participants were healthy and exercised an average of 30 to 60 minutes a day. None were sedentary.

Three evaluations were conducted, separated by 28 days. All of the men and women walked on a treadmill for 30 minutes to induce dehydration after being adequately hydrated the night before.

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The researchers compared their cognitive performance when the participants were hydrated and when they were dehydrated. The study included measures of concentration, reaction time, vigilance, learning, memory and reason.

One of the studies show young women who are mildly dehydrated experience headache, trouble concentrating and fatigue. There was no problem with their cognitive function but they perceived tasks as being more difficult more difficult.

In another investigation, the researchers found men who are mildly dehydrated felt tired, tense and anxious, but mood changes were more pronounced for women, found in this current study.

If you are not sure if you are well-hydrated Armstrong says check your urine, which should be pale yellow in color. Healthy people during eight 8 ounce glasses of water a day. The finding shows even mild dehydration can cause crankiness and other symptoms, perhaps by affecting neurons in the brain that signal other parts of the brain that regulate mood.

The Journal of Nutrition: doi: 10.3945
Mild Dehydration Affects Mood in Healthy Young Women
Lawrence Armstrong et al.
February 1, 2012

Image credit: Morguefile

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