staying hydrated and energized!
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Staying Hydrated and Energized!. Sports Nutrition PIE November 6-8, 2001 By Susan Mills-Gray, Nutrition Specialist. 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 - PowerPoint PPT PresentationTRANSCRIPT
Staying Hydrated and Energized!
Sports Nutrition PIENovember 6-8, 2001
By Susan Mills-Gray, Nutrition Specialist
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 waterWater essential to digestion and delivery of energyWater as sweat acts as a coolant to prevent body temperature overheating
Important to keep balanced
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
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
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
Effect of Dehydration On Performance
10%9%8%7%6%5%4%3%2%
2% 3% 4-6% >6%
Fluid Replacement Guidelines3– 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
Fluid Replacement Guidelines
Weigh before/afterMatch fluid intake to fluid outputDo not rely on thirst as indicatorCheck urine color
Fluid Replacement Beverages
Rapidly absorbedTastes goodNo gastro problemsWater – less than 60 minutesSports drink – longer than 60 minutes
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
Alcohol and Caffeine
Both impair performanceBoth are diureticAlcohol:– Increases urine = water loss– Depresses CNS:
• Affects balance and coordination• Early fatigue due to reduced glucose output
– Doesn’t contribute to glycogenCaffeine:– Carbonation takes up space– Increases blood pressure and heart rate
Electrolytes
Sodium, chloride, potassium– Responsible for:
• Body fluid levels• Muscle contractions• Nerve impluse
transmission
Sweat costs electrolytes– Especially sodium
Water loss concentrates electrolytesNeed extra when:– Ultra endurance in extreme
heat– Using plain water in ultra
endurance
Variety in diet ensures adequate electrolytesDon’t need sodium tablets
Sources
The Ultimate Sports Nutrition Handbook, Coleman and SteenGatorade Sports Nutrition Conference, 1999Sports Nutrition Guidebook, ClarkInvest In Yourself, Florida NETSports Nutrition, Missouri NETCoaches Corner, Gatorade Sports Science Institute