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Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred...

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Athletics and Nutrition
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Page 1: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Athletics and Nutrition

Page 2: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.
Page 3: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Basic goal of sports nutrition

• Ensure adequate fuel and fluid

• Preferred fuel depends on the intensity and duration of the physical activity.

• Fuel sources• Fat and Carbohydrate

Page 4: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Fuel Sources• Low intensity

• Fat is the primary source

• Ex. Walking

• High intensity• Carbohydrate is the primary

source

• During prolonged exercise, fat becomes an important fuel source.

Page 5: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Energy Sources

• *ATP*

• Phosphocreatine

• CHO – Glucose/Glycogen in glycolysis and TCA

• FA Oxidation

• Protein – Amino Acid Catabolism

Page 6: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Phosphocreatine

• Quick source for ATP in the muscle.

• When ADP accumulates - Phosphocreatine from muscle cells donate a P to produce Creatine and ATP.

• Creatine is converted to creatinine and excreted in the urine.

• Only in short intense exercise < 30 sec

Page 7: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Anaerobic Glycolysis

Page 8: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Anaerobic Glycolysis

• Oxygen limiting during exercise

• Faster

• Reduce pyruvate to lactate via lactate dehydrogenase to produce ATP

• Net Production:• 2 ATP• 2 Lactate

• Provides energy for 1-3 minutes• For shorter events (sprint, weight lifting)

Page 9: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Fates of Lactate

• Lactate (lactic acid) is acidic thus must be removed from the blood.• Impairs breakdown of glc and inhibits calcium

binding for muscle contraction• Convert back to pyruvate• Cori Cycle

Page 10: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Aerobic Glycolysis

• Oxygen based systems

• Used for long term exercises that require longer endurance

• Can produce a tremendous amount of ATP

• Can extract energy from fat

• Supplies energy more slowly• Lung -> blood -> muscle cells -> mitochondria

Page 11: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Anaerobic vs. Aerobic

• Anaerobic and aerobic energy systems work together to fuel athletes

• Most activities use ATP from both anaerobic and aerobic

• Short burst exercise – completely anaerobic (sprint)

• Marathon – completely aerobic

• Tennis, Basketball, Soccer, Swimming, 2 mile run• Both Anaerobic and Aerobic

Page 12: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Muscle Fiber Types

• Type I• Slow twitch – slow speed of contraction• Primarily use aerobic metabolism• Athletes with more type I have higher blood lactate

threshold• Facilitate long duration activities

• Type II• Fast twitch – fast speed of contraction• Anaerobic metabolism• Type IIa – aerobic and anaerobic• Type IIb – fastest and most glycolytic fiber type.

Page 13: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Muscle Fiber

• Most activities require both fast and slow twitch

• Activities that require more Type II• Deplete glycogen stores faster

• Ratio of slow to fast twitch depends on genetic predisposition

• 45% to 55% of people’s muscle fibers are slow twitch.

• Marathon runners can have up to 90% to 95% slow twitch muscle fibers.

Page 14: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Respiratory Quotient (RQ)

• RQ measures what type of fuel is being burned. Glycogen or Fat?

Amount of CO2 Produced

RQ =

Amount of O2 Consumed

Page 15: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

RQ

• RQ for certain nutrients:• Carbohydrate: 1.0• Protein: 0.8• Fat: 0.7

Page 16: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

How to calculate RQ

Oxidation of glucose (C6H12O6)

C6H12O6 + O2 CO2 + H2O

Nutrient + O2 CO2 + H2O

C6H12O6 + 6 O2 6 CO2 + 6 H2O

RQ = (6 CO2)/( 6 O2) = 1.0

Page 17: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

RER

• Respiratory Exchange Ratio (RER)

Amount of CO2 Expired

RER =

Amount of O2 Consumed

Page 18: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

RER

• Assumptions are valid for resting, steady state

• Can exceed 1.0 during heavy non-steady state.• Hyperventilation• Carbon dioxide output increases during

hyperventilation

• Not attributable to foodstuff oxidation

Page 19: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

How to measure RER?• Measured by gases exchanged at the mouth

• Indirect calorimetry• Open circuit• Closed circuit

Page 20: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

RER

• Assumption: exercising and consuming 2.0 L of O2 per min• Gas analysis: RER = 0.85• Expending 9.72 kcal/min (2.0 L of O2 per min X 4.86

kcal/O2)• Thus if exercising for 30 min then burning 292 kcal.

Page 21: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Michael Phelps’ Diet

Page 22: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Phelps’ Diet

Page 23: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Diet

• 60% Carbohydrate (Can be 70% for extreme exercise)

• Less than 30% fat

• About 15% protein

Page 24: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Carbohydrate

• Athletes depend on glycogen stores for energy

• Two types of glycogen in the body• Muscle glycogen• Immediate energy for muscle during exercise• Muscles lack glucose phosphatase to remove PO4 from

glucose.• Hitting the wall

• Liver glycogen• Fuels muscle and brain• At rest, brain and CNS use most of the glucose• Bonking/Crashing

Page 25: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Glycogen Depletion

• At the beginning of a race, the body uses muscle glycogen rapidly

• However as the race progresses, the body begins to use the glycogen much slower.

• After 3 hours, glycogen stores become depleted and the athlete experiences muscle weakness and confusion.

• As exercise intensity and duration increases, glycogen depletion is accelerated.• Ex. Sprinting uses muscle glycogen about 30 to 40 times

faster than walking.

Page 26: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Glycogen Depletion

Page 27: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Carbohydrate

• Guidelines for athletes recommend a high CHO diet during training (minimum of 60% of total calories)

• Helps to increase glycogen stores and increase endurance.

• Can prevent mental and physical fatigue.

• CHO should be mainly complex CHO

• Added sugars (simple) should be minimized

Page 28: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Complex CHO

• Polysaccharides

• Slower absorption rate

• Does not induce a strong insulin response

• Help to maximize glycogen stores

Page 29: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Complex CHO

Page 30: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Glycemic Index

• Ranking of food based on response to blood glucose level

• Area under the curve (AUC) of blood glucose level after ingestion of test food divided by the AUC of a reference food (glucose or white bread)

• Reflects rate of digestion and absorption of CHO-rich food

• CHO that break down quickly and release glucose into the bloodstream rapidly have high glycemic index.

• Low glycemic index = slower digestion

• Glycemic index scale is culture dependent

Page 31: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Glycemic Index

• Influenced by• Food form (particle size, texture, viscosity)• Degree of food processing and cooking• Presence of fructose or lactose• Ratio of amylopectin and amylose in starch

Page 32: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Glycemic Index

Page 33: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Carbohydrate Loading

• Carbo Loading

• Used in endurance athletes to maximize glycogen stores

• Recommended for activities lasting longer than 60 to 90 minutes

• Longer carbo loading days before event, longer exercise duration.

• Choice of carb: low glycemic index• Fruits, vegetables, whole wheat pasta and grains

• Women respond different than men• Glycogen storage more efficient 2 weeks before menstruation

Page 34: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Problems with Carbo Loading

• Which CHO to consume?

• Too much CHO can increase fat storage

• Depending on person, body can respond differently

• Decrease in protein and fat consumption

• Water?• 3 grams of water is need to store 1 gram of

glycogen

Page 35: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.
Page 36: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Carbohydrate

• Intake before exercise• 2 to 4 hours before exercise to replenish glycogen stores.• Athletes with GI distress should consume less CHO

• Intake during exercise• Drink fluids with low to moderate amount of simple CHO.• Plain water is adequate for short events (< 1 hr)• Consuming CHO before and after is more beneficial

• Intake after exercise• Can take up to 1 or 2 days to replenish glycogen stores.• Intake of CHO after an intense exercise is critical.• Replenish glycogen stores quickly• Prevent protein breakdown and enhance protein retention.

• Simple sugars, glucose, and sucrose effectively replenish glycogen, but not fructose.

Page 37: Athletics and Nutrition. Basic goal of sports nutrition Ensure adequate fuel and fluid Preferred fuel depends on the intensity and duration of the physical.

Recovery

• Need to replete glycogen stores

• Consume high glycemic index CHO• CHO important to avoid further muscle

catabolism

• Need protein as well to prevent wear and tear of muscles (rebuilding muscles)

• Adequate sleep and rest


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