The AEROBIC system.

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The AEROBIC system.
2
AEROBIC FACTS.
The only system to use oxygen. The slowest system
to contribute to ATP resynthesis, due to complex
chemical reactions. BUT, it is capable of
producing more ATP than either of the two
anaerobic systems.
3
AEROBIC FACTS.
Activated at the onset of exercise. Peak power
reached within 1-2min If exercise intensity
remains below 85 of MAX HR will remain the major
energy provider for extended periods of time
(2hours plus). See tabel 4.4 pp 101.
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How does the system work?

• During activity the aerobic system uses CHO for
  fuels. At rest or very low intensity activity it
  utilises fats (triglycerides) and CHO.
• At rest we burn 1/3 CHO and 2/3 fats.

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Aerobic system.

• Stage 1
• CHO is used as the fuel source.
• When there is sufficient O2, Glycogen is broken
  down into Glucose and Glucose into Pyruvic acid
  then energy is made available for ATP
  resynthesis.

ENERGY FOR ATP
CHO
GLYCOGEN
GLUCOSE
PYRUVIC ACID
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Aerobic Glycolysis.

• The process of breaking down Glucose for ATP with
  sufficient O2 is called aerobic glycolysis.
• With enough O2 present during this process there
  is no Lactic Acid accumulation.

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Aerobic Glycolysis

• This process takes place in the mitochondria
  within the muscle cell.
• These power houses produce ATP, which is then
  transported to the myosin cross bridges
  contraction.

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Aerobic three stage system.

• Stage 1
• CHO and Fats are used to produce energy.
• Fats are stored as triglycerides in blood.
  Glycerol and 3 free fatty acids (FFA) molecules.
• When this is broken down small amounts of energy
  are released for ATP used in basic bodily
  functions and low intensity activities.

GLYCEROL
FFA
FFA
FFA
GLYCEROLFFAFFAFFA
ATP for ENERGY
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Stage 2 Active

• CHO broken down in the presence of oxygen.
  Glycogen too glucose then pyruvic acid, where
  some energy is released in the Krebs cycle along
  with CO2.

Activity increases and O2 is provided CHO as
the preferred fuel (faster than FFA).
CHO
GLYCOGEN
GLOCOSE
PYRUVIC ACID
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Stage 3 Very active

• After the Krebs cycle we enter the electron
  transport system (E.T.C.).
• Here huge amounts of ATP are produced as well as
  heat, water.
• Large amounts of O2 must be available.

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AEROBIC SUMMARY
It requires oxygen which can be provided within
60 sec (90 of VO2 max) It involved more complex
chemical reaction than the other systems. It
prefers CHO. Fats can be used but require much
more O2 to break them down. It produced non
toxic/fatiguing by products and can be used
indefinitely. It provides 50 times more ATP than
the other systems. It provides significant energy
to all activities that are more than 1-2min in
duration