Thirsting for consistent hydration guidelines (The Times of Northwest Indiana)

After a summer without a string of 90-degree days, the first week in September will bring us precisely that from today through Thursday. Friday is supposed to be a shade cooler but still in the upper 80s.

Fortunately, four weeks into the fall sports season in Indiana (three in Illinois), the typical athlete should be heat acclimated. Still, in cross-country, football and soccer over the next few days, exertional heat illness (EHI) will be a legitimate concern. Consequently, athletic trainers and coaches will be pushing the fluids.

For the most part, that is exactly what they should be doing. Regrettably, though, more than a few of those charged with the care of our young — and not-so-young — athletes may now be plagued by some doubts. This is the result of a consensus statement regarding hydration published in the British Journal of Sports Medicine on July 30 — and featured in The New York Times last week.

According to NYT writer Gretchen Reynolds, “Dehydration during sports is rarely if ever dangerous, but overhydration is.”

Therefore, the BJSM article recommends drinking only enough to satisfy one’s thirst.

The scientific name for overhydration is Hyponatremia. Translation? Not enough (hypo) salt or sodium (Na+) in the bloodstream.

The BJSM article reports that the condition has been a traditional concern in endurance sports and military training. However, it cites three fatal cases in American football that occurred between 2008 and 2014. One in particular involved a Georgia high schooler who, suffering from muscle cramps, apparently ingested four gallons of water and Gatorade during practice. Shortly after arriving home, he collapsed and several days later, died.

Keep in mind that four gallons of fluid weigh 32 pounds.

Doug Casa, PhD, ATC, the director of the Korey Stringer Institute at the University of Connecticut, is the lead author of several position and consensus statements regarding EHI by the National Athletic Trainers’ Association. “The information (in the BJSM article) is good for the recreational athlete but not for the serious athlete,” he said.

As an example, he cited the typical football lineman who will experience a net loss of five liters (10 pounds) during a hot practice. “If he comes in at the end of practice and chugs an ice cold liter, he won’t be thirsty again for at least another hour. Thirst is not going to take (him) back to normal hydration.”

As for the assertion that dehydration has little to do with overheating, Casa replied, “During exercise in the heat, body temperature goes up a 1/2 degree Fahrenheit for every 1 percent loss in body weight. Hydration can be very protective.”

Beyond statistics, Casa has plenty of practical experience, “I’ve treated 215 cases of heat stroke in my career and nearly all of them were dehydrated.”

The key is knowing one’s sweat rate. That is why football players are expected to weigh in and weigh out of each practice. The athlete who has gained weight during a practice or game has been drinking too much. The more typical athlete, who has lost weight, needs to replace it with fluids and food.

If for no other reason, fluids should be pushed in the heat to enhance level of play. The data is even acknowledged in the BJSM article; a 3 percent drop in body weight (six pounds in a 200-pounder) will lead to a 10-15 percent drop in performance.


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