The Hub May 2016 | Page 7

Dietitians of Canada Sports drinks When you exercise you produce heat, which your body can help to control through sweating.When you sweat it helps cool your body but you can also lose water and electrolytes (e.g. sodium). If sweat, water and electrolytes are not replaced by taking in enough fluids then you become dehydrated. Dehydration can lead to health issues such as heat exhaustion and heat stroke. As little as 2 per cent dehydration (e.g. a 1.4 kg (3 lb) loss for a 68 kg or 150 lb – individual) can hurt your athletic performance. Sports drinks are specially designed to replace the sweat and electrolytes that you lose in sweat and to provide energy in the form of carbohydrate for active muscles and the brain. They can benefit a wide variety of athletes, including those: • With very high sweat rates (1L/h or more). • Exercising either very hard or for a long time (more than one hour) 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? • Water 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 may help you drink more fluids compared to plain water; this is especially true for children or teen athletes. 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. The salt in sports drinks improves hydration and may even help to prevent muscle cramps in some individuals. Sports drinks should contain at least 460 to 690 mg of sodium per litre although ultra-endurance athletes or athletes prone to cramping may require more. Sugar improves the taste, helps you drink more, keeps blood glucose from dropping, and helps fuel active muscles and the brain so that you can exercise longer and harder. Consuming between 30-60 g of carbohydrate per hour of activity can improve endurance and high intensity stop and go sport performance, prolong time to exhaustion, improve power output and delay fatigue. 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 g of carbohydrate per L. Your body is able to easily absorb anywhere from 30 to 80 g of carbohydrate per litre. Note that juice, pop, and energy drinks contain more than 100 g of carbohydrate per L, so they are not good for using during exercise. Some research does suggest that coconut water can be as effective as sports drinks for rehydration (especially if the coconut water is enriched with sodium), but further study is needed. Coconut water is often marketed to athletes as a more natural alternative to typical sports drinks. However, the nutrient content of coconut water is highly variable and many products often contain far less sodium and carbohydrates, but significantly greater amounts of potassium than sports drinks. Coconut water may also not be suitable to consume if you have a history of hyperkalemia (high levels of potassium in your blood). Many different types of athletes can benefit from the use of a sports drink that contains carbohydrate and sodium to help improve hydration and athletic performance. It is always important to try a sports drink in training first before using it in competition. Competitive athletes should consult a Registered Dietitian who specializes in sports nutrition to help them develop a hydration routine that meets their individual needs. Tell us on Facebook about your adventures with food this month, or tweet us @thehubWE #foodmatters May 2016 - The HUB 7