VCE Physical Education Unit 3 SAC 3 -Energy Systems and Fatigue/Recovery (copy)

For Victorian Certificate of Education Physical Education AOS 2

ATP Breakdown

• ATP is the energy source for all muscular movements. The ATP is split when a phosphate group is removed from the molecule. When it is split it releases energy.

Creatine Phosphate (Chemical)

• Chemical fuel contatining a high-energy phosphate for rapid release of energy.

• Limited CP Storage

Carbohydrates

• Sugar and starches e.g. bread, pasta, fruit, vegetables.

• The bodys preferred source of fuel under exercise conditions.

Fats

• Are a concentrated fuel source in dairy products, oils, nuts etc. Preferred fuel source at rest and during prolonged submaximal exercise.

Protein

• Protein if found in meat, fish, eggs etc. Used for muscle growth and repair.

  • Minimal Contribution to energy production during exercise.

ATP-PC System

• Fuel=Creatine Phosphate

• Intensity=Maximal <95%

• Rate=Explosive

• Yield=0.7 ATP PM

• Duration=0-10 seconds

Anaerobic Glycolysis System

• Fuel=Glycogen

• Intensity=High Intensity 95%-85%

• Rate=Fast

• Yield=2-3 ATP PM

• Duration=10-75 seconds

Aerobic Glycolysis System

• Fuel=Glycogen/Triglycerides

• Intensity=Submaximal 85%-70% or >70%

• Rate=Slow

• Yield=38 ATP PM or 441 ATP PM (triglycerides)

• Duration=75 seconds +

Factors Affecting Contribution

• The duration of the exercise

• The intensity of the exercise

• Whether sufficient oxygen is present

• Continuous exercise or intermittent exercise

• Available fuel sources

Writing a response

• All energy systems contribute to energy production

• ATP-PC starts continues to 6-10 seconds

• Anaerobic Glycolysis becomes more dominant

• Aerobic Glycolysis System increases but never becomes dominant.

  • Predominant Energy system would be ATP-PC for a 200m event.

Contributions from the energy systems depends on

• Duration

• Intensity

• Fuel Availability

  • Weather Conditions

Oxygen Uptake or Vo2

• The volume of oxygen able to be taken up by and transported to and used by the body for energy.

Vo2 Max Vs. Vo2

• Vo2 Max=The maximum volume of oxygen able to be used by the body.

  • Vo2=Is the rate of oxygen

Factors Affecting Oxygen Uptake

• Body Size

• Age

• Gender

• Training

  • Genetics

Oxygen Deficit

• Is the period of time at the start of the exercise where the oxygen demand exceeds.

Steady State

• Is the state in which oxygen equals oxygen demand

Oxygen Debt (EPOC)

• At the completion of exercise, oxygen consumption remains elevated, despite a reduction in the demand for energy.

Fast Phase of EPOC

• ATP Resynthesise

• CP Resynthesise

  • Restore oxygen to Myoglobin

Slow Phase of EPOC

• Return core temperature

• Convert Lactic Acid to h2o

• Lactic Acid converted to Glycogen/protein

• Restore heart rate

  • Restore other body systems

Relative VO2 Max

• Is a better measurement to compare athletes to one another.

Absolute VO2 Max

• The amount of oxygen breathed in per minute.

Before exercise (increased heart rate)

• Anticipatory Response

  • Warming the body up

ATP-PC System Fatiguing Factors

Accumulation of;

• ADP

• Inorganic Phosphates

• CP Depletion

Anaerobic Glycolysis System Fatiguing Factors

• Hydrogen Ions

Aerobic Energy System Fatiguing Factors

• Glycogen Depletion

• Central Nervous System Fatigue

• Thermoregulatory Fatigue

• Dehydration

Accumulation of H+ Ions

1. Hydrogen Ions Accumulate within the working muscles

2. The muscle cell becomes acidic (lower PH)

3. Inhibits Glycolytic enzymes that catalyse the breakdown of muscle glycogen.

4. Energy for ATP resynthesis produced at a slower rate.

5. Muscle contractions must slow down

Passive Recovery

• Replenishes PC in the muscles

Active Recovery

• Replenishes glycogen

PC Recovery Time

• 30 seconds = 70%

• 180 seconds = 98%

Fuel Depletion (Glycogen)

1. Depletion of intramuscular glycogen stores

2. Increased reliance on fat metabolism

3. Fats have a greater oxygen cost and a more complex breakdown.

4. Energy for ATP resynthesises produced at a slower rate

5. Muscle contractions must slow

Thermoregulatory

• Elevated Core Temperature

Thermoregulatory fatigue process

1. Elevated body temperature

2. Body redistributions a higher percentage of cardiac output at the skins surface.

3. Body cools down via evaporation

4. Increased rates of dehydration.

   • Decreased Plasma Levels

   • Increased Blood Pressure

   • Electrolyte Imbalance

   • Nervous Fatigue

LIP

The highest intensity where lactate removal and lactate production are balanced

LIP Intensity

85 % Max Heart Rate

55-70% VO2 Max

Working above LIP

• Increased Anaerobic Metabolism

• Increased Lactate and Hydrogen Ion Accumulation

• Decreased time to exhaustion