PED101 - Energy Systems

• PE
• Secondary Education

ENERGY SYSTEMS

How many energy systems
do humans have?

1. 1
2. 2
3. 3
4. 4

Energy Systems of human body

1. Aerobic System
2. Lactic Acid System
3. ATP-PC System

AEROBIC SYSTEM

In certain situations, the Aerobic System
can re-synthesize ATP without oxygen

True

False

Any time the term aerobic is used it always relates, involves, or requires oxygen

What fuel sources can the Aerobic System
use to re-synthesize ATP?

Fuels used in Aerobic System

Glycogen used as preferred source (Aerobic Glycolysis)

   - large glycogen stores in liver

   - can transport unused glycogen from other muscles

   - after 2 hours body's glycogen stores depleted (carbohydrate loading)

Fats also used as fuel

   - but delivery can be slow (time consuming to breakdown fatty body tissues)

   - requires large amounts of O2 (increased breathing)

Protein used as last resort! 

   - Muscles must be broken down to provide fuel.

What by-products are produced
in the Aerobic System?

What does the body do with the
by-products?

1. Store within muscle cell
2. Send to mitochondria
3. Expel into atmosphere
4. Diffuse into bloodstream

Exercise intensity

A measure of how "easy" or "hard" someone is working

Can be determined by a number of factors including:

• Rate of perceived exertion (RPE)
• Heart rate
• Blood lactate levels
• Speed (running/cycling/swimming etc)
• Jump height
• Throwing distance
• Weight lifted (ie. weight training)

AEROBIC SYSTEM

Advantages

Disadvantages

Relatively time consuming to re-synthesize ATP because must travel through mitochondria

Therefore can only service 

low-to-moderate exercise intensity

Huge pool of fuel sources to call on (glycogen, fats, protein)

Can supply ATP for hours-to-days

LACTIC ACID 

SYSTEM

Is the LACTIC ACID SYSTEM
Aerobic or Anaerobic?

Aerobic

Anaerobic

Is the LACTIC ACID SYSTEM

Aerobic or Anaerobic?

Is the LACTIC ACID SYSTEM

Aerobic or Anaerobic?

What is the only fuel source the LACTIC ACID SYSTEM can use?

1. Fats
2. Glycogen
3. Protein
4. Water

Lactic Acid System

• Anaerobic
• Glycogen (anaerobic glycolysis)

LACTIC ACID SYSTEM

• Glycogen only
• Anaerobic (O2 not required)
• Fast re-synthesis of ATP - does not need to travel through mitochondria
• Lactic acid produced as by-product

LACTIC ACID SYSTEM

Advantages

Disadvantages

If exercise intensity is high and prolonged, build up of Lactic Acid becomes overwhelming to maintain current intensity

Can only service high intensity 

exercise for 2 mins before exercise intensity must be reduced

Fast re-synthesis of ATP

Can service high-intensity exercise 

Limited pool of Glycogen in body

Once it is gone you "hit the wall"

> feeling of exhaustion

ATP-PC 

SYSTEM

What does the "PC" stand for
in ATP-PC?

1. Politically correct
2. Creatine Phosphate
3. Phosphocreatine
4. Post contact metres

Is the LACTIC ACID SYSTEM

Aerobic or Anaerobic?

Is the ATP-PC SYSTEM

Aerobic or Anaerobic?

What fuel source does the
ATP-PC use?

1. Glycogen (anaerobic)
2. Pyruvate
3. Phosphocreatine
4. ADP + Phosphate

What intensity of exercise does the ATP-PC system service?

1. Moderate
2. High
3. Moderate-to-high
4. Low-to-moderate

What byproducts are produced
in the ATP-PC system?

None

Lactic acid

ADP

Carbon dioxide

Bolt's 10m split times

1.  At what point did Bolt reach maximum speed?

2. At what point did Bolt significantly slow down?

3. Why did this occur?

Questions

Lactic Acid System

• Anaerobic
• Glycogen (anaerobic glycolysis)

ATP-PC SYSTEM

• Phosphocreatine only (anaerobic)
• Small store of PC in muscle cells
• Extremely fast re-synthesis of ATP
• No by-products
• Provides approx 10sec worth of energy
• Takes 3min to replenish PC stores