Staying well-hydrated while playing hockey is just as important as wearing the right equipment and sharpened skates, says Prof. Lawrence Spriet, Department of Human Health and Nutritional Sciences.
Previous research has focused on dehydration levels in athletes who play sports in hot weather. Hockey players were often overlooked in these studies because they play in chilled arenas and it was believed that they don’t sweat as much as other athletes.
That theory doesn’t hold water, says Spriet, because hockey is an intense, stop-and-go sport and players sweat as much as or more than athletes who play football, soccer or tennis in hot weather.
“We’re in awe of how hard they work,” he says of the Guelph Storm and World Junior hockey players who took part in his research. Hockey players can lose as much as two per cent of their body mass, equivalent to a 90-kilogram player losing 1.8 litres in fluid.
“You generate a lot of heat, and the body has to work quite hard to dissipate that heat, so it sweats a lot,” he says.
Add heavy equipment to a fast-paced game, and you have a recipe for dehydration. The body cools itself by sweating, but wearing multiple layers of clothing and equipment inhibits the body’s ability to release heat. Excessive sweating can lead to dehydration if those fluids aren’t replaced.
“When you lose fluid, your body has a harder time sending blood to the skin, and that’s how we get the heat to the periphery,” says Spriet. “Water absorbs that heat and dissipates it through sweating. It’s a very efficient system.”
But drinking water isn’t enough to stay hydrated. That’s why it’s important to drink a sports drink that contains both salt, which the body loses through sweating, and sugar, which fuels the brain and muscles.
One to two per cent dehydration is considered mild and won’t cause serious health problems like heat stroke, which can occur at four to six per cent dehydration, but it can impair a player’s performance on the ice by affecting reaction time, decision making and endurance.
Spriet’s research, which is funded by the Gatorade Sports Science Institute of Canada, is aimed at educating hockey players, coaches and trainers on the importance of staying hydrated to achieve optimal performance. His one-minute “infomercials” recently aired during the World Junior Hockey Championship.
In February and March 2010, Spriet and graduate students Matthew Palmer, Mark Linseman and Heather Logan conducted a study on campus involving 16 volunteers who played 70 minutes of scrimmage once a week over an eight-week period. Some of the players experienced a higher heart rate and core temperature at only one per cent dehydration. Their rating of perceived exertion, which refers to how hard they feel they are working, also increased.
“There’s more physiological strain on the body,” says Spriet. “The body does not seem to keep itself as cool.”
Sweat rates vary from person to person depending on their physiology and genetic makeup. People who sweat more lose more salt and become dehydrated faster. Regular physical training also causes the body to adapt by sweating faster and more profusely.
“Even in a well-trained person who is well-adapted to handle the heat that comes with exercise, if you let yourself get dehydrated, it compromises that system,” says Spriet.
But staying hydrated is easier said than done when players get caught up in the game. They need to get into the habit of sipping a sports drink every time they step off the ice, says Spriet. The more time players spend on the ice, the more important it is for them to stay hydrated so they can make it through the game.
One-third of World Junior hockey players Spriet tested were up to two per cent dehydrated. He also tested 20 Guelph Storm players over three games and found they lost an average of 3.5 litres of fluid.
Spriet advises adults to drink 500 to 700 ml of fluid 60 to 90 minutes before exercising. They should continue to drink fluids during their workout to keep their dehydration level below one per cent.
Professor Lawrence Spriet, from the Department of Human Health and Nutritional Sciences, sheds light on a critical aspect of sports performance: hydration in hockey players. Spriet's expertise in this domain is substantiated by extensive research and direct involvement with athletes from the Guelph Storm and World Junior hockey teams. His work dispels the misconception that hockey players don't sweat as much due to the cold environment they play in, establishing that they experience significant fluid loss, sometimes up to two percent of their body mass during play.
In his studies, Spriet demonstrates the rigorous physical demands of hockey, emphasizing its stop-and-go nature and the consequent intense sweating, which rivals or surpasses that of athletes in hot weather sports like football, soccer, or tennis. This fluid loss, coupled with the challenge of dissipating heat due to the heavy equipment worn during the game, makes dehydration a genuine concern for hockey players.
He underscores the intricate balance required for effective hydration, not just through water intake but also the consumption of sports drinks containing salt and sugar. This combination helps replenish lost electrolytes and provides the necessary energy for optimal brain and muscle function during gameplay.
Spriet's research delves into the impact of dehydration levels on performance, highlighting that even a mild one to two percent dehydration can affect a player's reaction time, decision-making abilities, and overall endurance on the ice. Moreover, he outlines the physiological strain on the body evident with increased heart rate, core temperature, and perceived exertion at mere one percent dehydration.
His work isn't limited to observations; he conducted a detailed eight-week study involving 16 volunteers engaged in hockey scrimmages, revealing the effects of dehydration on physiological strain and perceived exertion. Additionally, Spriet emphasizes the individual variances in sweat rates based on genetics and physical training, underlining the importance of adaptation and maintenance of hydration levels for optimal performance.
Practical advice from Spriet involves pre-exercise hydration routines, suggesting 500 to 700 ml of fluid intake 60 to 90 minutes before exercising, followed by continuous fluid intake during workouts to maintain dehydration levels below one percent. He advocates for habitual consumption of sports drinks while off the ice to ensure sustained hydration throughout the game, particularly crucial for players spending extended periods on the rink.
Spriet's research, backed by the Gatorade Sports Science Institute of Canada, aims to educate not just players but also coaches and trainers about the vital role of hydration in achieving peak performance in hockey. His findings have been disseminated through informative "infomercials" aired during significant hockey events like the World Junior Hockey Championship, emphasizing the importance of staying well-hydrated for optimal gameplay.
