Transcript Nutrition, Exercise & Sports - 35-206-202

NUTRITION, EXERCISE AND
SPORTS
CHAPTER 11
LEARNING OUTCOMES
• Explain the benefits of physical activity
• Discuss the energy sources for muscles and human
performance
• Describe how the body responds to physical activity
• Describe main nutrition concepts used when
designing diet plans for athletes
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LEARNING OUTCOMES
• Describe the fluid needs of athletes and how to
avoid dehydration and hyponatremia
• Describe how the composition of food eaten
before, during and after exercise training sessions
can effect performance
• Explain the role of ergogenic aids and describe their
effect on athletic performance
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TRUE OR FALSE?
• Most people in the US are physically fit.
• Athletes should eat immediately after training.
• Vitamin and mineral supplements improve athletic
performance.
• Everyone who exercises should consume sports
drinks.
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WHAT ARE THE BENEFITS OF EXERCISE?
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CHARACTERISTICS OF A GOOD FITNESS
PROGRAM
• Mode
• Duration
• Frequency
• Intensity
• Progression
• Consistency
• Variety
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MODE
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DURATION AND FREQUENCY
• Dietary Guidelines
• 30 minutes moderate physical activity for disease
prevention
• 60 minutes moderate to vigorous activity for
weight control
• 90 minutes moderate activity to maintain a weight
loss
• Frequency:
• Most days of the week
• Continuous or broken up?
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INTENSITY
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INTENSITY
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PROGRESSION, CONSISTENCY AND
VARIETY
• Progression
• Initiation (3-6 weeks): body adapts
• Improvement (takes 5-6 months): maximize intensity and
duration
• Maintain
• Consistency
• Variety
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ENERGY SOURCES FOR MUSCLE USE
• ATP: Immediately usable energy
• Lasts 2-4 seconds
• Phosphocreatine: Initial resupply of muscle ATP
• Re-forms ATP from ADP
• Concentration is 5 times greater than ATP
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CARBOHYDRATE
• Major fuel for short-term, high-intensity and
medium-term exercise
• Anaerobic (short-term, high-intensity)
• Glycolysis provides energy for 30 seconds to 2
minutes
• Carbohydrate is only fuel that is used in this
process
• Lactate is byproduct
• Aerobic (medium to high term)
• ATP supply is slower but greater
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CARBOHYDRATE
• Glycogen: storage form on carbohydrate
• Breaks down to glucose- used for anaerobic and
aerobic
• Muscle glycogen used for short events (<30
minutes)
• Liver glycogen used for long events-will start
to use blood sugar for fuel
• Exhaustion of glycogen stores: “Hitting the
wall”
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FAT
• Main fuel for
prolonged lowintensity exercise
(accounts for 5090% of fuel in this
type of activity)
• Fat provides more
energy, but is less
efficient
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FAT AS FUEL
• Training affects muscle use of fatty acids
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PROTEIN
• A minor fuel source during exercise
(gluconeogenesis)
• Eating more protein than what the body
needs will not build more muscle
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AMDR
• Acceptable Macronutrient Distribution Ranges for
Adults (as a percentage of Calories) for “regular”
adults.
• Protein: 10-35%
• Fat: 20-35%
• Carbohydrate: 45-65%
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DIETARY ADVICE FOR ATHLETES
• Protein Needs
• 1-1.7 g/kg body weight
• If an athletes needs are 2000kcals and she weighs 70kg, this
means she needs 70-120 grams (14- 24% of total kcal intake).
AMDR for Protein: 10-35%
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DIETARY ADVICE FOR ATHLETES
• Energy Needs vary widely
• Carbohydrate Needs
• 5-10 g/kg body weight depending on time/type of
exercise. If an athletes needs are 2000kcals and she
weighs 70kg, this means she needs 380-680g.
Boosting Glycogen Stores
• Carbohydrate Loading (What? Who? How?)
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DIETARY ADVICE FOR ATHLETES
• Fat Needs
• 15-25%, emphasis on unsaturated fats
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FLUID NEEDS
• Need to replace fluids lost through sweat
• Heat exhaustion
• Heat cramps
• Heat stroke
• Fluid Intake
• Goal is to lose no more than 2% body weight
• Before, during and after exercise
• Drink 3 cups for every pound lost during exercise
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HYDRATION
• Hyponatremia
• Sports Drinks
• Carbohydrates and
electrolytes (when
needed?)
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FOOD INTAKE
• Pre-exercise meal
• High carbohydrate, low fat
• Fueling during exercise
• Carbohydrate replenishment for events longer than 60
minutes
• Recovery meals
• 30 minutes and 2 hours after exercise 1-2 g of carbohydrate
per kg/body weight
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EXAMPLES
• Pre workout
• Goal: keep up blood
sugar but don’t upset
stomach
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Breakfast drinks
Cereal and milk, juice
Bread with peanut butter
Pasta and milk
Baked potato w/sour
cream
• Post workout
• Goal: Replace
glycogen stores to
help recover
• Early simple carbs like
juice, soda, sports drink,
chocolate milk
• Later complex carbs like
bread, potatoes, rice,
pasta
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ERGOGENIC AIDS
• Substances taken to improve exercise
performance
• Useful in some situations
• Creatine: increases phosphocreatine so may improve
performance in sports that require short bursts of
energy, muscle gain is partially from increased water
• Risks: kidneys
• Sodium bicarbonate: counter lactic acid buildup for
activities where lactate is rapidly made (wrestling)
• Risks: nausea and diarrhea
• Caffeine: stimulant, useful is some athletes who don’t
regularly drink coffee- NCAA does test
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