The thirst response doesn’t engage until the body has lost 1-2% of its total water volume. Mild dehydration, however, can potentially set in before the thirst response (at a loss of around 1.5% of total water volume). Hence the timeless advice: drink before you’re thirsty
But does dehydration really impact behavior? Researchers at the University of Connecticut Human Performance Lab decided to pursue the question. They assigned a set of tasks to a group of students who were well hydrated, and then assigned the same tasks to the same students while dehydrated. The tasks were designed to test the participants cognitive skills, including memory, reaction time, concentration, and reasoning.The thirst response doesn’t engage until the body has lost 1-2% of its total water volume. Mild dehydration, however, can potentially set in before the thirst response (at a loss of around 1.5% of total water volume). Hence the timeless advice: drink before you’re thirsty.
The women in the study showed little cognitive difference when dehydrated, though they did complain of headache, fatigue and lack of concentration. The male participants, on the other hand, experienced fewer physical symptoms, but experienced difficulty in memory and concentration based tasks. It is unclear why this difference exists, but the dehydration response is considered a survival mechanism designed to protect people from dangerous levels of dehydration.
Staying well hydrated is the key to elevated energy levels and productivity. Experts agree you should consume two liters of water per day to prevent the symptoms of dehydration. Starting your morning with a large glass of water is a good way to get a jump-start on the day, and keeping a water bottle can help with hydration throughout the rest of the day.