New study of salt in the sweat of PWHL players aims to help them hydrate better

New research is looking to help current and future female hockey players hit their highest potential by examining how athletes in the Professional Women's Hockey League sweat.

Under the study by the Gatorade Sports Science Institute about 100 PWHL players — including athletes from each of the four Canadian teams — will be tested to see how much they sweat during practices and games, and how much salt is in that sweat.

Each player will receive their individual results, and can use that data to fine-tune how they hydrate this season, said exercise physiologist Dr. Lawrence Spriet, who's leading the study.

"The analogy I often use is that no player in ice hockey would go on the ice if their skates were not sharpened the way they like, or they didn't have a stick they liked, or their equipment didn't fit properly," said Spriet, a professor emeritus of human health sciences at the University of Guelph.

"Why would you go on the ice not knowing what your hydration needs are, and also your nutrition? The hydration and nutrition part of it is a little harder to get a handle on, so that's the value of these sweat tests."

Montreal Victoire forward Marie-Philip Poulin said she's been sweat tested before and found the results useful — especially in situations like the four-overtime playoff battle her team weathered in May.

Athletes do everything they possibly can to improve their game and a personalized hydration plan should be part of that, she said.

"To me personally, I am getting a little bit older and you do want to find the edge, you do want to find that extra 0.01 per cent to make sure you're ready to go," said the Canadian superstar.

The sweat test is based on body mass, and sees a player get weighed without their equipment on and with an empty bladder before a practice or game. Everything they put into their body is then tracked over the session, with both the volume and type of liquid recorded.

At the end of the practice or game, they'll be weighed again to determine how much they sweat out.

When a player loses as little as 1.5 per cent of their body mass in sweat — about one litre for an athlete who weighs between 70 and 75 kilograms — their performance can decrease, Spriet said.

Their muscles may not work as well or their decision making could be reduced.

The most important thing for an athlete to ingest is fluid, he added, but looking at the composition of a player's sweat also allows a team's support staff to get a better idea of what that athlete needs in their water bottle on the bench.

"We're trying to keep them hydrated, we're trying to replace some of the salt that they lose, and we're trying to get some carbohydrate into the body to help keep them sharp as the game or practice nears the end," Spriet said.