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When drinking too much water can be deadly
CMU's sweat testing helps athletes hydrate safely, improve performance
2/14/2017 | Updated: 7/25/2019 12:27 PM
Hydrating safely
Gauze patches were applied to collect sweat from each player during football practice.
Players run through their normal practice routine. Miller combines environmental and sweat data to gauge the right level of hydration.
Miller analyzes the sweat for sodium and more to determine the level of hydration necessary for every position on the team.
When several high school athletes in the United States died after drinking large quantities of water and performance drinks to prevent muscle cramping, researchers at Central Michigan University and two other schools decided to take a deeper dive.
"Hydration is often recommended to prevent muscle cramps in amateur and professional athletes, but my studies show there isn't necessarily a link. In fact, the fear of cramping has caused some athletes to overhydrate, which can be dangerous," said Kevin Miller, a professor in the athletic training program at CMU. "I want to help CMU athletes and others avoid tragedy."
Drinking too much water or sports drinks dilutes the amount of sodium, and other electrolytes, in a person's blood. In some cases, this can cause a deadly condition called hyponatremia — a condition where excess water moves from the blood stream and into the brain. This can lead to brain swelling and, eventually, death.
Miller and his colleagues at the University of South Carolina and the University of Arkansas are collaborating to analyze the sweat rate and its content from athletes at their three schools. With this information, Miller can give fluid and diet recommendations to each athlete.
"I will be able to tell every athlete we've tested exactly how much fluid and sodium they need to consume to stay hydrated and healthy. This will help them perform better while also helping prevent hyponatremia," he said.
​"By understanding how much the average football player sweats in each playing position, I can make beverages tailored to replace the right amount of electrolytes for each player. I can make quarterback juice. I can make linebacker juice."​
— Kevin Miller, a professor in the athletic training program at CMU
The CMU Athletics staff is just as excited about mixing potentially life-saving science with athletic performance.
"We no longer have to guess about our athlete's fluid and electrolyte needs. This will do wonders for our athletic department and help our athletes recover faster during training and competition," said Jason Novak, head strength and conditioning coach for the CMU athletics department."
In his recent work with CMU athletic teams, Miller divided the athletes into two groups: those with and without a history of muscle cramps. The athletes were weighed before and after practice to determine their sweat rate — a measure of how much water they lose during a typical practice.
​"These results show that crampers and noncrampers lose similar amounts of fluid during exercise. It is unlikely that these fluid losses would contribute cramping."​
Participants also were outfitted with sweat patches that allowed Miller the ability to analyze how much sodium, potassium and chloride were in the athlete's sweat. Early results in about 100 CMU athletes show that those with a cramp history lose 70 milliliters more per hour than those without muscle cramp history.
"These results show that crampers and noncrampers lose similar amounts of fluid during exercise. It is unlikely that these fluid losses would contribute cramping," Miller said.
With the information he has collected, Miller says he can advise athletes and even craft sports performance drinks specific to each athlete's needs — whether they are a soccer player, gymnast or football player.
"By understanding how much the average football player sweats in each playing position, I can make beverages tailored to replace the right amount of electrolytes for each player," said Miller. "I can make quarterback juice. I can make linebacker juice."
In addition to CMU's football and field hockey teams, Miller also will complete sweat testing on the soccer and baseball teams. In the end, Miller and his colleagues will have collected data from more than 200 athletes across a variety of body weights, genders and sports.
ADDITIONAL CONTENT:
Miller collaborated with researchers from around the world to develop a position paper on hyponatremia, including diagnosis and treatment, in the British Journal of Sports Medicine.
Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference
Athletic Training; Health; The Herbert H. and Grace A. Dow College of Health Professions