Kevin Milne and Craig Harwood have a pretty strong suspicion that dehydration may result in a greater likelihood of concussion for many athletes.

Proving it, however, is the hard part.

A master’s student in human kinetics, Harwood recently presented results of a study examining the link between dehydration and concussion in San Diego at Experimental Biology 2014, an annual meeting hosted by the American Physiological Society of more than 14,000 scientists and exhibitors from dozens of scientific areas, including laboratory, translational, and clinical research.

Under the tutelage of kinesiology professor Dr. Milne, Harwood compiled data on 420 NCAA game-time concussions that occurred during more than 3,600 football games played outside over a five-year period from 2008 to 2012.

The pair noted that a loss of just two percent of the body’s water volume to dehydration can lead to a significant reduction in the amount of cerebrospinal fluid, which acts as a cushion to protect the brain inside the skull during jarring movements.

However, trying to establish a connection between dehydration and concussion is extremely challenging, Milne said. Conducting human or animal tests have numerous ethical dilemmas, and the best way to prove a correlation with real athletes would be to analyze hydration status before and during competition and most importantly, at the time of concussion.  Even that is fraught with difficulties, he added.

“The resources and time required to observe a sufficient number of concussions for analysis would be immense,” he said.

The next best way to examine whether there’s a connection, the pair decided, was to look at environmental conditions, including humidity, wind speed, and temperature, during those games. They hypothesized that if a relationship existed, they would see an increase in concussion frequency during games played under conditions health officials would call ‘heat stroke likely’ or ‘heat exhaustion likely,’ when there was a greater likelihood for dehydration.

However, given that most of the games they studied were played during more favourable conditions in the fall, and that concussion rates were consistent across all game time conditions, they had to conclude that environmental conditions do not impact concussion frequency in college football. But Harwood isn’t entirely persuaded by the findings and admits they’re far from conclusive.

“Personally, I’m still convinced that dehydration does have an influence on rates of concussion,” he said.

Milne and Harwood both acknowledge the project was a basic pilot study, with some very preliminary data, and they plan to apply to ethics and the NCAA to conduct more research on the subject, broadening the scope to other sports that are played in more extreme conditions.