Feeling Tired or Tense? Have a Drink … of Water!

Some experts recommend drinking 10 glasses of water a day. Others recommend drinking only when you feel thirsty. But a new study shows that even mild dehydration can affect our mood, lower our energy level, and cloud our thinking.

The University of Connecticut’s Human Performance Laboratory conducted two studies of young men and women. The subjects weren’t couch potatoes or high performance athletes. They were healthy and physically active with most getting 30 to 60 minutes of exercise each day.

Participants were properly hydrated the evening before being tested. The next day they walked on a treadmill to induce dehydration. Then they underwent cognitive testing for vigilance, concentration, reaction time, learning, memory, and reasoning. The results were compared to test scores obtained when they were fully hydrated.

Whether participants walked for 40 minutes on a treadmill or sat around relaxing, all experienced mild dehydration. (Mild dehydration is a 1.5 percent loss in the body’s normal water volume.)

“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,” stated Lawrence E. Armstrong, one of the studies’ lead researchers and professor of physiology.

“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.”

Effects of dehydration on women
Women appeared to be substantially more sensitive to the effects of low-level dehydration than men, whether at rest or during exercise. The women experienced

• headaches
• fatigue
• difficulty concentrating
• a perception that tasks were more difficult to perform

Effects of dehydration on men
The men experienced milder symptoms, including

• fatigue
• tension
• anxiety

Stay hydrated
Avoid the side effects of mild dehydration by drinking eight 8-ounce glasses of water a day, or approximately 2 litres of water daily.

Quick check for dehydration
Wondering if you could be suffering from dehydration? Check the colour of your urine. It should be a very pale yellow. The darker the colour, the greater the body is dehydrated. (Note that vitamins or medications can change the colour of urine.)

More research is required to determine why women are more sensitive to the effects of dehydration than men. In the meantime, don’t stay thirsty, my friends!