Lecture 13 Sports Nutrition (Aerobic Sports)

Question 1

Energy Sytems

Answer 1

1) ATP-CP
- lots of energy very fast, doesn’t last
- break down energy stored in muscles
- can provide a lot of energy very quickly
- lasts ~15 seconds (high V02 max%)

2) Anaerobic glycolysis
- 30-120 seconds (moderate V02max%)
- produces lactate as a by-product

3) Oxidative phosphorylation (aerobic metabolism)
- requires oxygen to produce energy (ATP)
- use glycogen, fat and produces CO2 and H20

• they don’t work independently, they’re all going simultaneously

Question 2

Endurance Sports and V02

Answer 2

• continuous endurance sports vs. endurance activities
• V02 and V02 max:
  
  • absolute V02 (L/min) vs. relative V02 (mL/kg/min)
• Anaerobic and lactate threshold:
  
  • aerobic –> anaerobic state

Question 3

ATP Production During Endurance Activities

Answer 3

• increase exercise intensity –> increase CHO and decrease fat intake %
• increase exercise intensity –> increase intramuscular source

Question 4

Exercise Training Principles

Answer 4

• Specificity:
• Overload: general adaptation syndrome (GAS)
• Progression: frequency, intensity, type and time (FITT Principle)

Question 5

Periodization

Answer 5

• planned long-term variation of the volume and intensity of training to prevent overtraining and promote optimal performance at the desired time

Question 6

Energy Requirement

Answer 6

• General prep: support desired changes in body composition
  
  • Aerobic development
  • High training volume (5-12+ hours/ week; lower training intensity)
• Transition / R&R
  
  • physiological and psychological recovery
  • low training volume and intensity (2-4 hours/week)
• Specific Prep: specific support / recovery for key specialized training
  
  • Anaerobic development, race-specific pace, increased specialized training
  • lower volume (~4-10+ hours/week; high intensity)
• Taper / Competition: avoid weight-gain with decreased training volume during taper
  
  • focus on race-specific intensity, neural muscular power
  • lower volume (3-8 hours/week; high intensity)

Question 7

Macronutrient Requirement

Answer 7

GP (g/kg/day):

• CHO: 7-10; ~60%
• FAT: 1.5-2; ~12%
• Protein: 1.5-1.7; ~12%

T/R&R (g/kg/day):

• CHO: 4-6; 57%
• FAT: 1-1.5; ~32%
• Protein: 0.8-1.2; ~11%

SP (g/kg/day):

• CHO: 7-10; ~66%
• FAT: 1-1.5; ~22%
• Protein: 1.5-1.7; ~12%

C (g/kg/day):

• CHO: 7-10; ~70%
• FAT: 0.8-1.2; ~12%
• Protein: 1.2-1.5; ~12%

Question 8

Recovery

Answer 8

• glucose consumption after exercise enlarges glycogen stores (by 300%)
  
  • consume a high-carb meal within 2 hours of completing exercise
  • select foods with a high GI

Question 9

Micronutrient Considerations

Answer 9

• Calcium/Vitamin D
• B Vitamins: metabolism
• Iron: anemia vs. sports anemia

Question 10

Carbohydrate Loading

Answer 10

• Endurance events >90 minutes
• 2-3% increase in glycogen storage
• may feel “weighted down”

Question 11

Day of an event

Answer 11

Carbohydrate intake

• 3-4 hours before; 3-4 g/kg/BW; mixed energy-yielding meal with carb drink
• 2 hours before; 1-2 g/kg/BW; light meal/snack or carb drink
• 1 hour before; 0.5-1 g/kg/BW; snack of carb drink
• Caffeine intake: CNS stimulant
  
  • world anti-doping agency: <15 micrograms/L (~10 cups)

Question 12

During an event

Answer 12

Hydrate and rehydrate

• 2L/hour of activity, but can only absorb 1L/hour
• replenish sodium >3h (hyponatremia prevention)

Carbohydrate intake (>1h)

• consuming 0.7g carb/kg body weight per hour
• combine glucose/fructose (2:1) to increase CHO absorption
• CHO “mouth rinse” (trick body into thinking we are consuming carbs)

Question 13

Enhance Fatty Acid Oxidation

Answer 13

• “training low, competing high” protocol
• 5 days LCHF diet can change fat oxidation
• translation to performance benefit is lacking
• implications:
  
  • decrease training intensity
  • may only be applicable to ultra endurance athletes