Do you have a drinking problem?

by barbaragarn

When playing hockey, you’re probably more dehydrated than you think.

One Canadian study indicated that a third (another said one-half) of players were dehydrated before they even got out of the locker room; skating in cool arenas doesn’t diminish dehydration rates, the scientist noted, because the arenas “aren’t that cool, players wear heavy equipment and helmets, and the game requires high-intensity bursts of skating.” (1, 2)

And the sweat rates were high for ALL positions, with a third of players across the board losing more than 1 percent of body mass during the game (2) Goalies have traditionally been reported as losing most of all players; JS Giguere is reported as losing 12 to 15 pounds per game. (3) However, the highest reported sweat rate for an athlete was Alberto Salazar’s during the 1984 Olympic marathon: 3.7 liters per hour! (4) That’s a little more than eight pounds per hour, or 16 CUPS pouring off him every 60 minutes!

Significant fluid loss–dehydration–drastically affects performance.

A loss of 2 percent body weight–in me, at 150 pounds, that’s about two pounds, or four cups–causes an increase in perceived effort and is claimed to reduce performance by 10 to 20 percent. (4) Less available water means less sweat to cool your exerted body. (5) And with less water in it, blood is thicker and harder to pump. This causes a strain on the cardiovascular system; heart rate rises three to five beats per minute for every 1 percent of fluid lost (5). Additionally, more viscous blood means the flow to skin decreases… which slows perspiration even more! (4)

And we’re likely not replacing fluid loss adequately.

In what one article calls “Nature’s dirty trick,” exercise actually suppresses thirst, so relying on “feeling thirsty” isn’t enough to make sure you’re adequately hydrated. (4) Drinking water isn’t enough. “Plain water causes bloating, suppresses thirst (and thus further drinking) and stimulates urine output (therefore is inefficiently retained) — a poor choice where high fluid intake is required.” (4) Replacing with plain water doesn’t address electrolyte needs: “The electrolytes sodium and chloride are necessary for proper body function and can prevent heat-induced muscle cramps.” (6)

Electrolytes control water use between different parts of the body, VERY important for increased activity, such as athletic purposes (8), though people’s needs vary: “The loss of sodium and chloride in sweat is adaptive and variable. For example, untrained males and females lose roughly twice as much as trained athletes.” (12) Most players fail to replace sodium (2), not least because “the ideal concentration would taste like sea-water, and palatability is vital” (4).

However, another article (6) claims that “It’s really not necessary to replace losses of sodium, potassium and other electrolytes during exercise since you’re unlikely to deplete your body’s stores of these minerals during normal training. If [you are] exercising in extreme conditions over 3 or 5 hours, you may likely want to add a complex sports drink with electrolytes.”

You’ll have to determine for yourself. I’ve concluded that, if a little salt will help (and it stimulates thirst, too–which, as noted above, is suppressed by exercise), then bring on the sodium. The National Trainers’ Association position statement says something similar: “Adding a modest amount of salt (0.3 to 0.7 g/L) to all hydration beverages would be acceptable to stimulate thirst, increase voluntary fluid intake, and decrease the risk of hyponatremia and should cause no harm.” (9)

Replacing carbohydrates is important in endurance sports, since its depletion is a factor in early fatigue (4): “the higher the exercise intensity, the more rapid the rate of carbohydrate utilisation and the sooner that glycogen stores are depleted” … but (and of special note for OUR sport), “if sweat rates are high and dehydration is rapid, then fluid replacement takes priority over carbohydrates.” (emphasis mine, 4)

Well, priority for carbs or fluid?? They’re not mutually exclusive, so I’m choosing a hydration strategy that has both. And I’m apparently agreeing with the American College of Sports Medicine: “Addition of proper amounts of carbohydrates and/or electrolytes to a fluid replacement solution is recommended for exercise events of duration greater than 1 hour since it does not significantly impair water delivery to the body and may enhance performance.” (10)

So what should you do?
Part 2 of this series will provide suggestions.

(I started this article and then realized that, even in summary, there’s too much info for one post. This will be a three-part series. There’s a ton of good information out there, please be sure to check the links for more details; they will also be cited in this article’s continuation. BG)

1. A study from Canada’s comically named “University of Guelph” that includes basic info about sports dehydration (though not how to combat it), but IS specific to hockey.
http://www.uoguelph.ca/news/2008/02/a_third_of_hock.html

2. Short, general article but hockey-specific.
http://www.cbc.ca/sports/hockey/ourgame/columns/minor_menu/2009/02/drink-your-way-to-optimal-performance.html

3. JS Giguere’s sweat test on Gatorade site
http://www.gatorade.ca/en/giguere/

4. British article with good technical information about carbohydrates, sodium, electrolytes–and recommendations for those components in fluid replacement beverages.
http://www.pponline.co.uk/encyc/0824.htm

5. In-depth article about tennis in general, but extremely useful hydration info for any sport.
http://www.tennisserver.com/set/set_02_04.html

6. Basic article about proper sports hydration
http://sportsmedicine.about.com/od/hydrationandfluid/a/ProperHydration.htm

7. “Nutrition and Hydration for Performance” by a sports drink company, complete with “pee chart.”
http://www.snowsportgb.com/docs/Sponsors/Nutrition%20and%20Hydration%20for%20Performance%20%20-%20SSGB.pdf

8. Layperson’s guide to chemical nature of sports drinks
http://www.mamashealth.com/access/edrink.asp

9. Seven page position statement of the National Trainers’ Association on fluid replacement for athletes, published in the Journal of Athletic Training
http://www.nata.org/statements/position/fluidreplacement.pdf

10. American College of Sports Medicine position stand on exercise and fluid replacement (brief)
http://www.ncbi.nlm.nih.gov/pubmed/9303999

11. Review of sports drinks
http://www.athleteinme.com/ArticleView.aspx?id=358

12. Fluids and Electrolytes During Exercise
http://www.athleteinme.com/ArticleView.aspx?id=256

13. Post-exercise caloric intake, including carbs and protein
http://sportsmedicine.about.com/cs/nutrition/a/aa081403.htm