Feeling a bit cranky? Lazy, maybe? Do the kids seem to be whining more than usual? The answer may be simple, and it has nothing to do with summer doldrums.
You may all be dehydrated.
Even mild dehydration can alter a person's mood, energy level, and ability to think clearly, according to two studies recently conducted at the University of Connecticut's Human Performance Laboratory.
The tests showed that it didn't matter if a person had just walked for 40 minutes on a treadmill or was sitting at rest — the adverse effects from mild dehydration were the same.
The test results affirm the importance of staying properly hydrated at all times and not just during exercise, extreme heat or exertion, says Lawrence E. Armstrong, one of the studies' lead scientists and a professor of physiology.
Most people only think about drinking water when they are thirsty; but by then it may already be too late.
"Our thirst sensation doesn't really appear until we are 1 [percent] or 2 percent dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform," says Armstrong, an international expert on hydration who has conducted research in the field for more than 20 years. "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."
In tests involving the young women, mild dehydration caused headaches, fatigue, and difficulty concentrating, according to one of the studies, which appeared in a recent issue of The Journal of Nutrition.
In tests involving young men, mild dehydration caused some difficulty with mental tasks, particularly in the areas of vigilance and working memory, according to the results of the second study. While the young men also experienced fatigue, tension, and anxiety when mildly dehydrated, adverse changes in mood and symptoms were "substantially greater in females than in males."
In order to stay properly hydrated, experts like Armstrong recommend that individuals drink eight, 8-ounce glasses of water daily. Fluids are also available through many foods, such as fruit. However, it is best to avoid high-sugar sodas, energy drinks, sports drinks and even juices. If kids insist on these, dilute them with water.
An easy way to monitor hydration status is by checking the color of your children’s urine, which should be pale yellow. Urine that is dark yellow indicates greater dehydration.
"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," says Harris Lieberman, one of the studies' co-authors and a research psychologist with the U.S. Army Research Institute of Environmental Medicine. "In both sexes these adverse mood changes may limit the motivation required to engage in even moderate aerobic exercise. Mild dehydration may also interfere with other daily activities."