By: Pearle Nerenberg, Sports Dietitian
IF YOU START A GAME DEHYDRATED OR DEHYDRATE MORE THAN 2% OF YOUR BODY WEIGHT DURING A GAME YOU ARE NOT OPTIMIZING YOUR ON-ICE PERFORMANCE.
If you start a game dehydrated or dehydrate more than 2% of your body weight during a game you are not optimizing your on-ice performance.
Thomas found out he can improve his game by doing this simple 2 part test.
First, we checked if Thomas was drinking enough water to wake up hydrated by taking a urine sample and a morning weight on 3 consecutive days. A special tool is used to measure hydration level with urine if you don’t have this tool you can use pee color, but this is not always an accurate way to tell if you’re hydrated. Thomas made sure to weight himself after using the washroom so his weight does not reflect what is actually just waste in his body.
On game day the morning routine was the same plus there was an extra urine test at the rink to see if his morning hydration level was the same as his pre-game hydration level.
The second part of the test was to check how much water Thomas lost during his hockey game. A pre-game weight is taken right before he gets his equipment on. Any liquid he drinks from now on will come from his special water bottle so that we can measure exactly how much fluid he had. The water bottle can be weighed for increased accuracy.
During the game a spectator or coach can record active playing time, can help assess performance, and remind the player being tested to drink only from their special water bottle and refrain from eating or using the bathroom until after the post-game weight is taken.
Goalies are known to lose more water than forwards and defense due to their heavy equipment. And, concentration during a game is crucial for performance. Losing 2% of body weight can impact concentration abilities and cost Thomas in reaction time.
The post-game weight should be taken as soon as the player has undressed, dried off, and put on the same dry outfit they were wearing for the pre-game weight.
How did Thomas do?
It turns out Thomas is like most young teens and woke up dehydrated on each of the 3 days we tested. His game day test shown here highlights the fact that most often if the player is waking up dehydrated they are showing up to the game still dehydrated.
Thomas should aim to hydrate more throughout the day. He was given a first target of fluid to drink based on his body weight. It is important that the goal is displayed in many ways to show how hydration needs can be easily met.
What about during the game? How much water (i.e. sweat) did Thomas lose?
His games are not intense enough or long enough to cause him to have huge sweat losses reaching that 2% of weight lost which is known to decrease athletic performance. When it comes to larger teens or adults, well then we’re getting into larger water losses. Adult male hockey players have been known to lose as much as 2 liters of water during a game, that is more than 4 times what Thomas lost. For these players we do dehydration rates that provide them with in-game drinking goals and post-game recovery of hydration goals.
If you are looking for more information on hydration testing or sports nutrition, Consult a sports dietitian from the hockey nutrition network. www.HockeyDietitians.ca