Download NUTRITION IN ATHLETES

NUTRITION IN
ATHLETES
Melinda A Scott, D.O.
Primary Care Sports Medicine Physician
Orthopedic Associates of Dayton, Inc.
Dayton, Ohio
April 23rd, 2015
Introduction
• The sports nutrition paradigm
Gain
energy
Eat
more
Train
hard
Build
muscle
Burn
fat
Introduction
• Why is nutrition in athletes important?
Achieve and maintain ideal body mass
Maintain proper hydration
Preserve lean body mass
Maximize oxygen delivery (reduce fatigue)
Promote recovery from training
Improve performance
Introduction
• Most athletes, parents and coaches are confused about
appropriate nutrition for training and competition
• Study in 2014 showed coaches do not have a great understanding
of nutrition
• Can be very complex
• Constantly changing views on nutrition
• Have to deal with diet fads, supplement use
• Need to set goals for balance between performance and
body composition (weight control)
Goals for today:
How do all
these play a
part in an
athlete’s
training and
performance?
What is the
best timing and
combination of
these to
maximize
performance?
Hydration
Carbohydrates
Proteins
Fats
Vitamins/Minerals
Hydration
• Greatest impact on training, performance and
recovery
• Average daily requirements for active
individuals
• Men 3.7 L/day
• Women 2.7 L/day
• Elite marathoners can sweat 2 L/hour
De-Hydration
• How is dehydration defined?
• 1% or more loss of body weight due to fluid loss
• Severe dehydration is greater than 3% loss of body weight due to
fluid loss
• Dehydration in an athlete can reduce their…
• Strength
• Endurance
• Coordination
• Mental acuity
• Thermoregulation
De-Hydration
• Thirst starts when already 1-2% of body weight has
already been lost
• ALREADY DEHYDRATED!!!
• In severe dehydration, even with oral rehydration
solutions, rehydration can take up to 18-24 hours
Fluid Replacement
Pre-exercise
• 16-18 oz. (½ liter), 1 ½ to 2 hours before exercise
• 8-16 oz, 15 minutes before exercise
During exercise
• 4-8 oz. every 15 minutes of exercise
Post-exercise
• 24 oz. for every pound of weight loss
Fluid Replacement
• Beverage options
• Less than an hour of
exercise
• H2O is best
• Over an hour of exercise
• Need to replenish glycogen
stores
• 6-8% glucose/electrolyte
solution (GATORADE) or
carbohydrate protein mixture
• TASTE IS IMPORTANT
• Not juice – has high
concentration of fructose,
decreased absorption rate,
GI distress
Hyperhydration
• Glycerol
– Aid in rehydration
– Protect against
dehydration
– Enhance performance
– Great for hot environments
– Side effects
• Headaches, blurred vision,
GI distress (low)
Biochemistry
Biochemistry – Don’t Panic!
Biochemistry Refresher
• ATP
• Immediate energy source
• Creatine phosphate
• Helps regenerate ATP anaerobically
• Energy source for short bursts
• Carbohydrate
• Breaks down to glucose  Glycolysis
• Short to moderate exercise
• Glucose stored as Glycogen – limited amouts
• Fat
• Stored in muscle as triglycerides
• Can be a great source of energy if enough is consumed in diet over a period of
time
• Low-intensity, long duration exercise
• Protein
• Amino acids not a major source of energy during exercise
• Only 6% of energy used
• Important in repair and recovery of muscle
Carbohydrates
• NOT ALL CARBS ARE
CREATED EQUAL
• Whole unprocessed carbs from
plant sources are preferred
• Combination with protein and fat
• Glycemic index – low vs high
• When are refined carbs better
than whole carbs?
• Raisins vs energy gel
• Strength Cond Res. 2007
Nov;21(4):1204-7.
Carbohydrates
• General guidelines
• Preexercise
• 1.8g/lb body wt, 3-4 hours before exercise
• 0.5g/lb body wt, 1 hour before exercise
• Whole carb foods are better, breakdown slower
• Simple carbs 30-60 minutes prior to exercise can cause rebound
hypoglycemia
Carbohydrates
• General guidelines
• During exercise
• > 1 hour exercise need carbohydrate ingestion
• Sports drink q15 minutes can work well
• Can do solid forms of carbs as well
• Hydration?
• Glucose alone not as beneficial
• Carb rinse – no effect on performance overall or on hydration
Carbohydrates
• General guidelines
• Post-exercise
• Differing views
• Protein and carbohydrate mixture/combination may be best for restoring
muscle glycogen
• 1:3 protein-carbohydrate ration is recommended
Carbohydrates
• Daily diet
• Athlete will require more carbohydrates during training than
competition
• Daily diet is important
• High in carbohydrate with mixture of protein and fats
• 5-10g/kg/day (can be as high as 10-12g/kg/day)
• Helps increase muscle glycogen stores
Carbohydrates
• Daily diet
• Men vs Women
• Women use less glycogen and more fat as energy compared to men
• Women do not require as many daily carbs compare to men
• Women benefit from a diet higher in fat (30%)
Carbohydrates
Endurance vs. Strength Exercise
• Strength exercise
• Uses less muscle
glycogen/carbohydrate
• May need less carbs in their
diet
• Endurance exercise
• Long distance athletes
benefit from carb intake pre,
post and during exercise
• Overall need higher daily
carb intake
Proteins
• Athletes have an
increased protein need
compared to the normal
population
• Sedentary 0.8g/kg/day
• Athletes 1.2g to 2.0g/kg/day
• Ideal protein sources
• Should contain all essential
amino acids (EAA)
• Animal proteins
• Meats, eggs, milk
• Soy
• Lower quality
• Plant sources that are
missing EAA
Proteins
• Nitrogen balance
• Definition: AA contribution = excretion rates
Negative
Nitrogen
Balance
Stimulated by
overtraining and
fasting
Muscle protein
breakdown and
prevents muscle
growth
Positive
Nitrogen
Balance
Ideal for building
lean body
mass/performance
Must consume
optimal amounts
of high-quality
protein
Muscle Recovery
• Role of protein
• Consuming at least 20g of protein mixed with carbohydrates within
30 minutes post-exercise for muscle recovery
• Helps gain strength and lean body mass
• Leucine is the stimulant for this process
• Research suggests that protein consumed pre-exercise can have
the same effect on lean body mass
Protein Consumption
• Individuals with liver or kidney damage
• These individuals should refrain from excessive amounts of protein
(>2.8g/kg/day)
• Extremes…..
• Dwayne “The Rock” Johnson
The Rock’s Daily Diet
• Meal 1
• 10 oz cod
• 2 whole eggs
• 2 cups oatmeal
• Meal 2
• 8 oz cod
• 12 oz sweet potato
• 1 cup veggies
• Meal 3
• 8 oz chicken
• 2 cups white rice
• 1 cup veggies
• Meal 4
• 8 oz cod
• 2 cups rice
• 1 cup veggies
• 1 tbsp fish oil
• Meal 5
• 8 oz steak
• 12 oz baked potato
• Spinach salad
• Meal 6
• 10 oz cod
• 2 cups rice salad
• Meal 7
• 30 grams casein protein
• 10 egg-white omelette
• 1 cup veggies
• 1 tbsp omega-3 fish oil
The Rock’s Daily Diet
Before
After
Fat
• Natural, minimally processed sources preferred
• Animal and plant fats
• Balance between land-based, marine-based and omega-3 rich
plants
Fat
• Diet
• High fat/moderate to low carbs for >7 days increase fat oxidation
• Delays feeling of exhaustion
• May feel heavier when exercising
• Women
• Need 30% of calories as dietary fat
• Use fat more readily compared to men
• Weight in lbs x 0.45 = grams of fat/day
Good Fat!
• High performance fats
• Oleic acid
• Olive and canola oils
• Long-chain omega-3, EPA and DHA
• Marine oils
• Short-chain omega-3 linoleic acie
• Flax, walnut, hemp and pumpkin oils
• Conjugated linoleic acid (CLA)
• Dairy products
• Medium chain triacylglycerols (MCT)
• Coconut oil
Good Fat
• Reduces inflammation and breakdown of soft tissues
• Maintains sex hormone concentrations
• Bone preservation
• Helps reduce mental depression from over-training
• Helps absorption of fat-soluble vitamins
• Vit A, D, E, K
Vitamins & Minerals
• Regular exercise may cause greater needs
• B vitamins
• Increased energy needs  Increased vit B needs
• Act as cofactors in metabolism of fats, proteins, and carbohydrates
• Vit D
• Need 600 IU/day up to 1000-2000 IU/day in active individuals
• Can be easily be deficient
• Debates about effect on performance
• Iron
• Transports O2 in red blood cells
• Helps in energy metabolism during exercise
• Highly active individuals are at risk for Fe deficiencies
• Female
• Endurance runners
• Vegetarian athletes
Fuel for Specific Activities
• Short Sprint
• Last 10-12sec
• Equal ATP/CP to Carbohydrate (50/50)
• Short intense events
• Last 4-6 minutes
• Primarily carbohydrates (94%), ATP/CP (6%)
• Moderate events ie 10k run
• Lasts 30-45 minutes
• Carbohydrates (60%), fat (40%)
• Marathon event
• Carbohydrates (75%), fat (20%), protein (5%)
• Long low intensity activities
• Walking 5-8 hours
• Fat (65%), carbohydrate (35%)
Take Home Points
• Education of the athletes and coaches is KEY
• Hydration is utmost importance to performance
• Each athlete should have an individualized approach
• Nutrition is constantly evolving
References
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