1. Anaerobic Glycolysis System
Energy systems
Anaerobic
Aerobic
Anaerobic Glycolysis System
Aerobic Energy System
ATP-PC System

2. Introduction Energy for muscular contractions comes from ATP
ATP is created from our food and drink – released from CHO, Fats & Proteins
All food and drinks consumed contain nutrients that your body requires for healthy growth, repair of the body and energy for bodily functions
ATP is produced by 3 energy pathways. Each is the main provider under specific exercise conditions but all contribute to energy across all degrees of activity

3. The Basics ATP-PC System:
Provides energy for the resynthesis of ATP through the breakdown of PC without oxygen
>95% max HR
Anaerobic Glycolysis Energy System:
Provides energy for the resynthesis of ATP through the breakdown of glycogen through a series of chemical steps that do not require oxygen
>85% max HR
Aerobic Energy System:
Provides energy for the resynthesis of ATP through the breakdown of various fuels (mainly glycogen and fats) through a series of chemical steps that require oxygen
<80% max HR

4. A closer look....
The 3 energy systems do not function independently or one at a time, but work together via interplay of the 3 systems
Contribution is determined by the intensity & duration of the exercise.
Depends on
Duration
Intensity
Presence of Oxygen
Depletion of chemical and food fuels during exercise

5. ATP (Adenosine Triphosphate)
Your body needs ATP for basic body functions and activity throughout your whole life
ATP is composed of an adenosine molecule joined to 3 phosphate molecules by chemical bonds. When a chemical bond is broken energy is released. The phosphate molecule breaks off and energy is released leaving ADP
ATP is continually produced/resynthesised by ADP joining with Pi and this can occur anaerobically or aerobically

6. Capacities of the 3 energy systems
ATP-PC
Anaerobic Glycolysis
Aerobic
CHO
FATS
Fuel Source PC
Glucose
Glycogen
FFA
Triglycerides
Rate
Most Rapid
3.6 moles/min
Rapid
1.6 moles/min
Slow
1.0 moles/min
Slowest
<1.0 moles/min
Yield
Very Small
<1
Small 2
38 (glucose)
39 (glycogen)
129 (FFA)
387 (Triglycerides)
Dominant Time Period
0 – 10 secs
10 – 60 secs
2 – 90 minutes
4 + hours
Event
Power
Speed
Endurance
Ultra - endurance
Capacities of the 3 energy systems

7. Anaerobic Respiration
Anaerobic respiration involves the release of a little energy, very quickly from the incomplete breakdown of glucose without using oxygen, inside the cells.
The Process of Anaerobic Respiration
1. Glucose is made available by the breakdown of glycogen stored in the working muscles.
Energy for muscles to contract and create movement
2. The glucose is used by the muscles of the body to produce energy, without the use of oxygen.
Glucose
Lactic Acid
3. This process creates lactic acid, which passes back into the blood for removal.
VCE Physical Education - Unit 3

8. How Anaerobic Respiration Happens1 2 3
Glucose is transported to the muscles of the body via the blood.
Glucose passes into the muscles cells and is used to produce energy for muscular
contractions.
Anaerobic respiration
produces lactic acid
as a waste product.
Facts about Anaerobic Respiration
During anaerobic respiration, your muscles are not supplied with enough oxygen.
The lactic acid builds up due to the shortage of oxygen.
The lactic acid build-up will soon make your muscles feel tired and painful, so exercising anaerobically can only be carried out for short periods of time.

9. The rest is converted into heat to warm the body.
Anaerobic Respiration is how sprinters produce the energy that is used in short periods of ‘all out effort’ - high intensity.
Oxygen cannot reach the muscles fast enough, so anaerobic respiration is used.
Glucose produces…
Some is used for
muscle contractions,
creating movement.
Lactic acid quickly builds up & makes the muscles feel tired & painful. ‘All out effort’ cannot last for very long!
The rest is converted into heat to warm the body.
VCE Physical Education - Unit 3

10. ATP-PC Energy System

11. ATP-PC Energy System
Quickest system for breaking down PC (phosphocreatine) to form ATP
Breaks down PC to form ATP anaerobically (no oxygen).
Provides the bulk of ATP during powerful and explosive efforts eg. throwing, jumping, short sprints
PC stores require passive recovery (most rapid way to replenish PC)
ATP & PC are stored in the muscles.
70% PC replenished in 30secs, 98% in 3mins & 100% in 10mins
Dominant system for the first 10 seconds of high intensity exercise
Used in fast, powerful movements.
Once PC stores are depleted, they body must use glycogen through the anaerobic pathway.
Provides peak power first 5secs

12. Anaerobic Glycolysis energy system

13. Anaerobic Glycolysis energy system
This system provides the bulk of ATP production during high intensity sub-maximal efforts eg. 200m sprint
More complex reactions than the ATP-PC system therefore ATP is supplied at a slower rate.
Peak power 10 – 60 secs
An example of the lactic acid system is a 400m run or a team game when the performer is required to undertake repeated sprints that do not provide sufficient recovery time for the ATP – PC system

14. Anaerobic Glycolysis energy system
Glycogen is broken down to release energy in the absence of oxygen (Anaerobic glycolysis)
During maximal exercise the rate of glycolysis (the rate of breaking down glycogen) can increase 100 times to the rate of rest. It produces lactic acid which contributes to fatigue (decrease intensity/muscles not contracting)
The breakdown of Glycogen in the absense of oxygen produces a metabolic by product called lactic acid which contains fatiguing Hydrogen ions

15. Anaerobic Glycolysis energy system
Lactic acid makes the hydrogen ions in
the muscle decrease inhibiting the affect
of glycolytic enzymes (enzymes
Responsible for the breakdown of
glycogen)
The Lactic Acid System
is activated to a significant
extent if performance intensity
exceeds that anaerobic threshold
(point at which lactic acid begins
to accumulate this is often
expressed as occurring at 85%
maximum heart rate or 70% V02 max

16. The Process of Aerobic Respiration
Aerobic respiration involves the release of energy from the slow breakdown of glucose using oxygen, inside the cells.
Water
Glucose
1. Glucose and oxygen are transported to the working muscles by the blood.
Energy for Muscles
to contract and
create Movement
2. Glucose and oxygen are then used by the muscles of the body to produce energy.
Carbon Dioxide
3. This process creates carbon dioxide and water.
Oxygen
4. The carbon dioxide passes back into the blood for removal.
VCE Physical Education - Unit 3

17. How Aerobic Respiration Happens…1 2 3
Glucose and oxygen are carried by the haemoglobin in the
red blood cells.
Glucose and oxygen pass into all the muscle cells of the body and is used to help produce energy for muscular contractions.
Aerobic respiration produces carbon dioxide & water as waste products.
Facts about Aerobic Respiration
During aerobic respiration, the heart and lungs supply the muscles with plenty of oxygen.
The carbon dioxide is breathed out via the lungs, while the water is lost as sweat, urine or in the air we breathe out as water vapour.
As long as the muscles are supplied with enough oxygen, exercising aerobically can be carried out for a long period of time.

18. Aerobic respiration is how marathon runners produce the energy that is used in long periods of less intensive effort.
Some is used for
muscle contractions,
creating movement.
The rest is converted
into heat to warm the body.
Glucose and
oxygen produce…
Water, which is carried away by the blood and excreted through the lungs, sweat and urine.
Carbon dioxide, which is carried away by the blood & excreted through the lungs.

19. Aerobic energy system

20. Aerobic energy system Slowest contributor to ATP resynthesis
Produces more ATP than anaerobic systems – the system can create 38 molecules of ATP from one molecule of glucose, whereas anaerobic glycolysis creates only 2. The oxygen used in this aerobic system allows for a more complete breakdown of glucose.
The Aerobic System is the major contributor of energy production in prolonged exercise and at rest.
Contributes in maximal intensity exercise: 45% in 60 sec effort
Providing the intensity of activity remains below 85% of max HR this system will continue to be the major contributor for extended endurance events e.g. Triathlon, 10,000 m event, marathon

21. Aerobic energy system
With the rich oxygen supplies in the aerobic system fat is able to become a significant contributor to ATP production.
Fat releases more molecules of ATP but at a much slower rate than the release from glucose and requires much more oxygen, therefore CHO are the preferred energy source.
The body’s supply of fat exceeds even the physical requirements of an elite athlete so the aerobic system can theoretically operate for unlimited work period.