Sports Nutrition: Sports Drinks
Sara Oldroyd MS RD Utah State University Extension
HYDRATION
Are You Drinking Enough?
Recommend 9 cups for women and 13
cups for men as a starting point
SKIN
FLUIDS
LUNGS FOOD URINE METAB. FECES
Loss of 1%-2% of body weight in fluid Thirst signal Loss of 2% or more of body weight causes
muscle weakness
Lose significant strength and endurance
Loss of 10%-12% Heat intolerance Loss of 20% Coma and death
General guidelines: Drink 3 C of fluids per each pound of weight loss during activity Check urine color Drink fluid freely 24 hours before event Drink 1 ½ -2 ½ C two-three hours before event Consume ½ - 1 ½ C every 15 minutes for events lasting longer than 30 min. Lose no more than 2% of body weight
TOO MUCH WATER
Overburden the kidneys
Low blood electrolyte
concentrations
Blurred vision
SPORTS DRINKS
Recommended for activity > 60 minutes Help maintain blood glucose level and blood volume Delay “bonking”
Supply electrolytes <60 minutes Nutrients are easily replaced by diet
Sports Drinks – What’s in them?
Carbohydrate Sodium Potassium Other Vitamins and Minerals
SPORTS DRINK BREAKDOWN
20 18 16 14 12 10 8 6 4 2 0 WATER DRINK #1: 6% DRINK #2: 8% DRINK #3: 9% FLUID ABSORPTION (ml/cm/hr)
GATORADE
History
Nutrition Facts: 50 Cal/8 fl oz 0 g fat 110 mg Sodium 30 mg Potassium 14 g Carbohydrate (5%)
SPORTS DRINK WITH PROTEIN
“Protein added to a sports drink improves
fluid retention.”
2.5 % Body Weight loss During a 3-hr recovery
“Failure of protein to improve time trial
performance when added to a sports drink.”
Cycling time trial Adequate amounts of fluid No additional benefits
Bottom Line: Sometimes helpful (but not
as often as most people think) The “lay public” is sold on the simple concept that sweat should be replaced with a beverage similar in composition to sweat. They disassociate the act of eating from electrolyte replacement
SPORTS DRINKS Its not just GatoradeTM anymore…
Sports Drinks with Stimulant
Caffeine
Guarana Green tea
Ephedrine
Acts as stimulant to raise metabolism,
but more often used, less of an effect.
Other Ingredients
Herbal supplements Not enough evidence May interact with medications
B vitamins Release energy from food Taurine: Amino Acid Plays a role in muscle contraction?
Caffeine Amts in different drinks
Red Bull: 80 mg/8 oz
Coffee: ~125 mg/8 oz Chocolate bar: 30 mg (theobromine) Tea: 40 mg/8 oz
Caffeine WILL help performance in most cases NCAA and IOC have banned caffeine at certain levels
Take Care
Be cautious about energy drinks!
THANK YOU
RESOURCES
Presentation:
http://extension.usu.edu/saltlake/htm/nu trition/lunchnlearn USDA MyPyramid: www.mypryramid.gov Australian Institute of Sport: http://www.ais.org.au/nutrition/HotTopic s.asp
CITATIONS
Contemporary Nutrition, Gordon Warlaw
and Anne Smith Food, Nutrition & Diet Therapy, Jacqueline Berning www.mayoclinic.com