Dehydration Impairs Cognitive Performance
Drink water to ward off brain fog.
Keep reminding clients to drink plenty of fluids. New research shows that cognitive abilities—attention, coordination, complex problem solving and reaction time—begin to decline with as little as 1% loss of body mass from dehydration, with more severe impairments showing up at 2%. Dehydration affects attention first and with more severity than other cognitive abilities.
Principal investigator Mindy L. Millard-Stafford, PhD, director of the exercise physiology laboratory at Georgia Institute of Technology, Atlanta, said that cognitive abilities affected in the study included “maintaining focus in a long meeting, driving a car [and doing] a monotonous job in a hot factory that requires you to stay alert.” She added that “higher-order functions like doing math or applying logic also dropped off.”
Researchers based their findings on a review and meta-analysis of 33 studies with a total of 413 participants. “There’s already a lot of quantitative documentation that if you lose 2% in water, it affects physical abilities like muscle endurance or sports tasks and your ability to regulate body temperature,” said Millard-Stafford. “We wanted to see if that was similar for cognitive function.”
The study was published in Medicine & Science in Sports & Exercise (2018; doi:10.1249/MSS. 0000000000001682).
Shirley Eichenberger-Archer, JD, MA
Shirley Eichenberger-Archer, JD, MA, is an internationally acknowledged integrative health and mindfulness specialist, best-selling author of 16 fitness and wellness books translated into multiple languages and sold worldwide, award-winning health journalist, contributing editor to Fitness Journal, media spokesperson, and IDEA's 2008 Fitness Instructor of the Year. She's a 25-year industry veteran and former health and fitness educator at the Stanford Prevention Research Center, who has served on multiple industry committees and co-authored trade books and manuals for ACE, ACSM and YMCA of the USA. She has appeared on TV worldwide and was a featured trainer on America's Next Top Model.
