Energy Sources for Physical Performance (Chapter 1)

Sources of Nutrients (Fuels):

Fats: 

• Are used for long duration events at low intensity
• They release more energy that carbohydrates however they are more dificult to breakdown (require more oxygen)
• They are broken down through Aerobic lipolysis

Carbohydrates:

• Are used for short duration events at high intensity
• When the stores are depleted it is known as hitting the wall
• They can be broken down through either Aerobic or Anaerobic glycolysis

Proteins:

• They are primarily used for growth and repair
• These are rarely used. Extreme cases only (Starvation)

Energy Systems:

The ATP-CP System:

• Last for short duration (0-10sec)
• 50% is restored in around 30sec
• 100% is restored in around 3min
• Works without oxygen (anaerobically)
• There are no by-products

Latic Acid System:

• Short term (10sec - 2min)
• By-product is lactic acid
• Works without oxygen (anaerobically)
• Occurs at a high intensity
• fuel = glycogen

Aerobic System:

• With oxygen (aerobically)
• There are no by-products
• Uses…