Staying Hydrated and Energized!

1. Staying Hydrated and Energized! Sports Nutrition PIE November 6-8, 2001 By Susan Mills-Gray, Nutrition Specialist

2. What’s the Big Deal about Water? • Distribution of water in the body: • 65% intracellular • 35% extracellular • 70-75% of muscle mass is made of water • Water essential to digestion and delivery of energy • Water as sweat acts as a coolant to prevent body temperature overheating Important to keep balanced

3. The Road to Dehyrdration • The most common cause of fatigue • Occurs from sweat loss: • Contributes to fatigue • Increases risk of developing heat illness • Body temperature rises as byproduct of working muscles

4. The Road to Dehydration • Large losses thru sweat impair performance • Blood usually used to transfer oxygen to muscle diverted to skin to reduce heat • Competition for blood between muscle & skin puts greater demand on cardiovascular system • Blood volume reduced due to sweat loss • Sweat first comes from extracelluar, then intra : • Mostly from muscle and skin –protects brain/organs

5. The Road to Dehydration • Body is programmed to protect cardiovascular function at expense of body temperature regulation • Skin blood flow + sweat rate reduces body fluid = • Raised body temp = dehydration • As little as 2% body weight loss may impair performance

6. Effect of Dehydration On Performance 10% 9% 8% 7% 6% 5% 4% 3% 2% 2% 3% 4-6% >6%

7. Fluid Replacement Guidelines • 3 • 3 hours before 2-3 cups • 2 • 2 hours before 2 cups • 1 • 1 hour before 1-2 cups • Time Out! • Time out for fluids • ½ cup every 15 minutes • 2 cups of fluid for every pound lost

8. Fluid Replacement Guidelines • Weigh before/after • Match fluid intake to fluid output • Do not rely on thirst as indicator • Check urine color

9. Fluid Replacement Beverages • Rapidly absorbed • Tastes good • No gastro problems • Water – less than 60 minutes • Sports drink – longer than 60 minutes

10. Fluid Replacement Tips • Sports drinks: • Contain carbs and sodium • Glucose + sodium increases fluid & carb uptake in gut • Need to be 6 to 8% carbs • Higher than 8% carbs (sodas, fruit juices, some sports drinks) • Takes longer to be absorbed • Abdominal cramps • Nausea • Bloating • Diarrhea • Allows athlete to retain water without inhibiting thirst

11. Alcohol and Caffeine • Both impair performance • Both are diuretic • Alcohol: • Increases urine = water loss • Depresses CNS: • Affects balance and coordination • Early fatigue due to reduced glucose output • Doesn’t contribute to glycogen • Caffeine: • Carbonation takes up space • Increases blood pressure and heart rate

12. Water loss concentrates electrolytes Need extra when: Ultra endurance in extreme heat Using plain water in ultra endurance Variety in diet ensures adequate electrolytes Don’t need sodium tablets Electrolytes • Sodium, chloride, potassium • Responsible for: • Body fluid levels • Muscle contractions • Nerve impluse transmission • Sweat costs electrolytes • Especially sodium

13. Sources • The Ultimate Sports Nutrition Handbook, Coleman and Steen • Gatorade Sports Nutrition Conference, 1999 • Sports Nutrition Guidebook, Clark • Invest In Yourself, Florida NET • Sports Nutrition, Missouri NET • Coaches Corner, Gatorade Sports Science Institute