New study on PWHL players’ sweat aims to help current, future female athletes

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 Guelph University. 

“So 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. 

In addition to a player’s individual results, the broader findings will also be included in a larger study by the Gatorade Sports Science Institute. That research already includes about 300 to 400 athletes at the highest levels of several other sports, Spriet said. 

“What they’re really trying to do is to build a database on hydration experiences and habits needs, if you will, for a wide range of professional or near professional female athletes,” he said.

Similar data already exists for male athletes, and having research that’s designed for women is crucial, said Jayna Hefford, the PWHL’s executive vice-president of hockey operations. 

“We’ve all tried to perform and live, really, with research that isn’t specific to women generally. I think outside of sport, we even find that,” she said. “So, this type of study, I think it shows the commitment of Gatorade to growing with us and growing with the sport, and elevating women, female athletes.”

The study comes as women’s sports continues to explode in popularity across North America. 

The PWHL is adding two new teams — the Vancouver Goldeneyes and Seattle Torrent — this season, and the WNBA will get its first Canadian franchise in the Toronto Tempo next year. 

“When you look at the prominence of female sport and the athletes, it’s hard to imagine that there’s only been (very little) research on women who have been performing at a high level for a long time,” Hefford said. 

“So it’s exciting to think where the sport can go, and specifically for us in our league and our athletes, how their performance can be impacted as we continue to invest in them.”

This report by The Canadian Press was first published Nov. 18, 2025.