Sports Drinks

Their role in hydration for athletic performance  

Why Do I Need to Drink During Exercise?
Anyone who exercises can be at risk for dehydration. When we exercise we produce heat, which our bodies can help to control through sweating.

If our core body temperature climbs just a few degrees Celsius, then heat illness, heat stroke and even death can occur. When we sweat we can help cool our bodies but can become dehydrated. Many athletes can lose 0.4 to 2.0 L of sweat (1 to 4 lb loss) in just one hour, especially if exercising in the heat either intensely or for a long time.

• With very high sweat rates (1L/h or more)
• Exercising either very hard or for a long time including endurance and team sport athletes
• Exercising in hot and humid conditions or while wearing protective sports equipment such as with hockey and football

What Should I Look For in a Sports Drink?

WaterThis is the first and most important ingredient.Make sure your sports drink is not carbonated so that it is easy to drink and doesn't make you feel full or bloated.

Flavour Adding flavour to a sports drink helps athletes drink more than when they are given water alone.

Sodium Sweat contains more than water. Have you ever noticed a white powder on your workout clothes or skin? That is the salt you lose in sweat. Adding salt to a sports drink can not only help to prevent muscle cramps, but it can actually help you to stay better hydrated. Sports drinks should contain at least 300 to 700 mg of sodium per liter although ultra-endurance athletes or athletes prone to cramping may require more.

Carbohydrate (sugar)Sugar improves the taste, helps you drink more, keeps blood glucose from dropping, and helps fuel active muscles so that you can exercise longer and harder. Carbohydrates help to keep you from "bonking" (hitting the wall), which occurs when muscles run out of fuel, usually after 2 or more hours of activity.Consuming between 30-60 grams of carbohydrate per hour of activity can improve endurance and high-intensity stop and go sport performance, prolong time to exhaustion, improver power output and delay fatigue. On the other hand, too much carbohydrate can upset your stomach and hurt your performance. To prevent stomach and intestinal upset be sure your drink has no more than 80 grams of carbohydrate per liter (40-70 grams/L is best). Note that juice, pop, and energy drinks like Red Bull all contain more than 100 grams of carbohydrate per litre, so they are not intended for using during exercise.Look for a combination of carbohydrates, including glucose, sucrose, fructose and/or maltodextrin on the label, which helps to speed absorption versus taking just one type of carbohydrate.
 

Bottom Line
Many different types of athletes can benefit from the use of a sports drink that contains the appropriate amounts of carbohydrate (40-70 g/L) and sodium (300-700 mg/L) to help improve their athletic performance. It is always better to try a sports drink in training first before using it in competition so that athletes may determine which brands and flavours they prefer. Athletes who are concerned about selecting the appropriate sports drink should consult with a Registered Dietitian who specializes in sports nutrition to help them develop a hydration routine that meets their individual needs.

Written by Heather Petrie, M.Sc., P.Dt. and reviewed by Jennifer Sygo, Dt.P. and Heidi Smith, Dt.