Download Concepts and Controversies Energy Systems Overview Energy

Nutrition for Active Living:
Concepts and Controversies
Energy Systems Overview
• ATP/CP Energy System
• Anaerobic Energy System
• Aerobic Energy System
NSCA South Carolina State Clinic
Alicia Powers, PhD
Energy Systems Components
• Adenosine Triphosphate (ATP)
• Creatine phosphate (CP)
• Carbohydrate
– Glucose
– Glycogen
• Fat
Adenosine Triphosphate (ATP)
• Basic form of energy for cells
• Breaking the last high energy bond releases
energy
• Muscle cells store enough ATP to supply 1-3
seconds of energy
• Additional ATP is made by creatine
phosphate, carbohydrate, fat and protein
– Free fatty acids
– Triglycerides
• Protein
– Amino acids
Creatine Phosphate (CP)
• A high energy compound
• Broken down to regenerate ATP
• Can support activity for an additional 10
seconds
Anaerobic Metabolism
• Without oxygen
• Produces ATP quickly
• Glucose is partially
broken down to yield
2 ATP through
anaerobic glycolysis
– Results in lactic acid
accumulation
– 10 seconds to 3
minutes
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Aerobic Metabolism
Aerobic Glycolysis
• With oxygen
• Glucose can be completely broken down
through aerobic glycolysis to produce
36-38 ATP
– 3 minutes to 4 hours
• Fatty acids can be metabolized
aerobically to produce 129 ATP
– 20 minutes to …
• Amino acids can be metabolized
aerobically to produce 15 ATP
Energy Systems Overview Duration
Energy Systems Overview Components
Energy Systems Overview –
Duration and Components
Energy Systems Overview –
Intensity and Components
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Factors Leading to Fatigue
• All activities
–
–
–
–
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Inadequate physical training
Mental fatigue
Inadequate energy intake
Dehydration
Delayed nutrient delivery
• Activities that primarily use ATP/CP
– Depleted creatine phosphate
• Anaerobic and aerobic activities
– Inadequate carbohydrate intake
• Aerobic activities
– Anemia
Dehydration
• Decreases blood volume
– Decreases sweat rate
• Increases body temperature and increases
heart rate
– Causes fatigue
Inadequate Energy Intake
• Increased caloric needs to sustain high levels
of physical activity
• Typically need 35-50 kcals / kg body weight
– Sedentary males and females
• 31 kcals/ kg body weight
• 150 lb person – 2100kcals
– Recreational athlete
• 33-38 kcals/ kg body weight
• 150 lb person – 2250-2600kcals
– Endurance and strength athlete
• 35-50+ kcals/ kg body weight
• 150 lb person – 2400-3400kcals
Delayed Nutrient Delivery
• Fluids and nutrients must be absorbed
through the small intestine before
these can enter the blood and be used
by muscle cells
• Factors that delay the rate that food
and drink leaves the stomach (gastric
emptying) will delay nutrient delivery
Delayed Nutrient Delivery
• Factors that delay gastric emptying of
fluids and food
– Fluid or food
• High fat content
• High intensity activity
– Fluid
• Low volume of fluid consumed
• Carbohydrate concentrations <4% or >8%
• Dehydration
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Depleted Creatine Phosphate
• Creatine supplementation appears to improve sprint
performance and the amount of strength gained
• Creatine supplementation does not improve aerobic
performance
• Creatine can be obtained through the diet from meat
• Long term effects of creatine supplementation are
not known
Inadequate Carbohydrate Intake
• Athletes should
consume 55-65%
of kcals as
carbohydrates
• However, most
athletes do not
consume enough
kcals to fuel
activity, which
leads to a
distorted view of
carbohydrate
intake
Nutrient Needs for the Athlete
•
•
•
•
Macronutrient needs
Micronutrient needs
Fluid needs
Sample meal plan
1715 cal
294 g carb (68%)
1200 cal
210 g carb (70%)
Macronutrient Needs
• Carbohydrate
– 55-65% kcals
– Females: 6-8 g/kg body weight
– Males: 8-10 g/kg body weight
• Fat
– 20-25% kcals
– 1 g/kg body weight
• Protein
– 12-20% kcals
– Endurance: 1.2-1.5 g/kg body weight
– Strength: 1.6-1.8 g/kg body weight
Macronutrient Needs
Macronutrient Needs
• Maximizing carbohydrate intake
– Begin exercise with full glycogen stores
– Consume carbohydrate period to exercise
• 100 grams 1 hour before exercise or
• 300 grams 3 hours before exercise
– If activity lasts more than 60 minutes, consume
carbohydrate during activity
• 30-60 grams of carbohydrate per hour
• 20oz. Bottle of Gatorade has 35 grams of carbohydrate
– Consume carbohydrate after physical activity to
replenish glycogen stores
• 50-100 grams of carbohydrate immediately after (200400kcals)
• 2 hour window of opportunity maximizes storage
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Macronutrient Needs
Macronutrient Needs
15 grams of carbohydrate
1 cup of Gatorade
1 whole grain waffle
1 packet of oatmeal
1 slice of whole grain bread
1 granola bar
1 small orange
2 carrots
2 broccoli spears
1 veggie burger
10 ounces of skim milk
1 T. pancake syrup
Micronutrient Needs
• Athletes may need additional nutrients
such as
– B vitamins
– Calcium
– iron
30 grams of carbohydrate
2 oz. whole grain bagel
1 cup whole grain cereal
¾ cup whole grain pasta
1 cup chili with beans
1 cup apple juice
1 large apple
1 banana
45 grams of carbohydrate
1 cup brown rice
4 Fig newtons
1 energy bar
½ cup Grape Nuts
Fluid Needs
• Before exercise
– Maintain adequate fluid intake prior to event
– Drink about 2 cups of fluid 2 hours before exercise
to allow for absorption and excretion before event
• During exercise
– Drink 1 cup every 15 minutes
– Many athletes prefer cool, flavored beverages
– Exercise > 60 minutes can be enhanced with
beverages containing 6% carbohydrate and small
amounts of electrolytes
• After exercise
– Consume 16 ounces of fluid for every pound of body
weight lost during exercise
Sample Meal Plan
Early morning snack
1 slice whole wheat toast
1 tsp. jam
½ cup apple juice
Afternoon snack
1 oz. string cheese
1 oz. pretzels
1 cup grapes
Breakfast
½ cup orange juice
1 cup strawberries
1 egg
1.5 cups whole grain cereal
1 cup 1% milk
1 slice whole wheat toast
1 tsp. margarine and jam
Dinner
Mid morning snack
1 whole grain bagel
1 tsp. margarine and jam
1 cup water
Lunch
4 oz. turkey on whole wheat
with mayo, lettuce, and tomato
1 apple
1/3 cup potato salad
8 oz. cranberry juice
Chicken stir-fry
4 oz. chicken with 2 cups broccoli,
red pepper, carrots
2 tsp. vegetable oil
1 T. soy sauce
2/3 cup cooked rice
1 orange
1 cup iced tea
Evening snack
1 cup 1% milk
5 graham crackers
Totals
3,000 calories
Carbs: 483 g (63%)
Protein: 139 g (18%)
Fat: 64 g (19%)
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