Source: Georgia Institute of Technology
Summary: According to a new study, just two hours of vigorous yard work in the summer sun without drinking fluids could be enough to blunt concentration.
Cognitive functions often wilt as water departs the body, researchers at the Georgia Institute of Technology reported after statistically analyzing data from multiple peer-reviewed research papers on dehydration and cognitive ability. The data pointed to functions like attention, coordination and complex problem solving suffering the most, and activities like reacting quickly when prompted not diminishing much. As the bodies of test subjects in various studies lost water, the majority of participants increasingly made errors during attention-related tasks that were mostly repetitive and unexciting, such as punching a button in varying patterns for quite a few minutes. There are situations in life that challenge attentiveness in a similar manner, and when it lapses, snafus can happen. The study findings were published in the journal Medicine & Science in Sports & Exercise.
The researchers have been concerned that dehydration could raise the risk of an accident, particularly in scenarios that combine heavy sweating and dangerous machinery or military hardware. There’s no hard and fast rule about when exactly such lapses can pop up, but the researchers examined studies with 1 to 6% loss of body mass due to dehydration and found more severe impairments started at 2%. That level has been a significant benchmark in related studies. The researchers looked at 6,591 relevant studies for their comparison, then narrowed them down to 33 papers with scientific criteria and data comparable enough to do metadata analysis. They focused on acute dehydration, which anyone could experience during exertion, heat and/or not drinking as opposed to chronic dehydration, which can be caused by a disease or disorder.
Millard-Stafford said, “You can have too much water, something called hyponatremia”, “Some people overly aggressively, out of a fear of dehydration, drink so much water that they dilute their blood and their brain swells.”
More Information: Matthew T. Wittbrodt et al, “Dehydration Impairs Cognitive Performance”, Medicine & Science in Sports & Exercise (2018). DOI: 10.1249/MSS.0000000000001682