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Even Mild Dehydration Affects Mood

The view from inside a wave
A recent study reports that the mild dehydration, which occurs even before we perceive thirst, could be enough to alter mood and energy levels.

US researchers revealed that the negative effects of  mild dehydration (defined as 1.5% loss in normal water volume) at were the same whether people were sitting at rest or active and exercising.

The study tested two groups of young men and women, who were “healthy, active individuals, who were neither high-performance athletes nor sedentary – typically exercising for 30 to 60 minutes per day.”

While mildly dehydrated (either from gentle walking activity or simply from being sedentary), the subjects were put through a succession of cognitive tests that measured vigilance, concentration, reaction time, learning, memory, and reasoning. The results were compared against a separate series of tests when the individuals were not dehydrated.

For young women, mild dehydration caused headaches, fatigue, and difficulty concentrating. The researchers said that female subjects also perceived tasks as more difficult when slightly dehydrated--though they said there was no substantive reduction in their cognitive abilities.

For the men, mild dehydration caused some difficulty with mental tasks, particularly in the areas of vigilance and working memory. The researchers reported that young men also experienced fatigue, tension, and anxiety when mildly dehydrated, though they added that adverse changes in mood and symptoms were "substantially greater in females than in males, both at rest and during exercise."

The results assert the importance of staying properly hydrated at all times, and not just during exercise, extreme heat, or exertion. "Our thirst sensation doesn't really appear until we are 1 or 2 percent dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform," said the lead author. "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," he affirmed.
"Even mild dehydration that can occur during the course of our ordinary daily activities can degrade how we are feeling – especially for women, who appear to be more susceptible to the adverse effects of low levels of dehydration than men," explained a co-author of the research. “Mild dehydration may also interfere with other daily activities, even when there is no physical demand component present," he suggested.

Source: Mild Dehydration Affects Mood in Healthy Young Women

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  1. Interesting article. Thanks Dr Know.
    What about electrolytes? How does this fit into the picture?

    1. Of course, electrolytes are extremely important, but would become more important to focus on if losing lots of water through perspiration (which also makes you lose electrolytes).


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