A2 PE physiology

• Energy systems rarely work in isolation eg games player have high and low intensity 
• Energy is provided by each system 
• The contribution id determined by intensity and duration of exercise

Shotputter- 90% ATP/PC System 

Marathon Runner- 5% Lactic Acid System 95% Aerobic System 

800m Runner- 30% ATP/PC System 65% Lactic Acid System 5% Aerobic System 

Tennis Player- 70% ATP/PC System 20% Lactic Acid System 10% Aerobic System

Netball Player- 60% ATP/PC System 20% Lactic Acid System 20% Aerobic System 

To measure intensity- 

• Calculate % of max HR ( 220-age = max ) 
• Or vO2 max- Amount of O2 taken on in 1 min 

• Threshold of ATP/PC 10 seconds 
• Threshold of Lactic Acid 3 minutes
• When aerobic system can nolonger supply energy quick enough it goes back to anaerobic 
• This is called blood lactate accumulation 
• The conc of blood lactic acid in the blood increases quickly 
• norm- 1-2mm of LA per L of blood 
• 4mm + is when OBLA is reached 
• This point varies due to aerobic fitness
• Untrained- OBLA at 50% of vO2 max 
• Trained- OBLA at 85% of vO2 max 
• Trained athletes can get rid of LA and supply O2 to working muscles
• Stores of fuels vary according to fitness levels
• Increased muscle size , Increased aerobic metabolism , Increased enzyme activity 

ADVANTAGES-

• Doesnt require 02
• PC stored in the muscle cells as a readily avaliable energy source
• Small compound so quick reaction
• Automatically stimulated by a decrease in ATP and increase in ADP
• Provides energy for high intensity actions
• No fatiguing by-products
• PC can be resynthesised quickly 

DISADVANTAGES-

• Only small amounts of ATP/PC stored in muscles 
• 1;1 ratio 
• Lasts 8-10 seconds 

ADVANTAGES-

• Large glycogen stores in muscle/liver 
• 2;1 ratio 
• Fewer reactions than the aerobic system 
• Quicker supply of energy 
• GGP and PFK enzyme activated due to decrease in PC
• Lasts between 10-180 seconds 
• Can work areobically and anaerobically 

DISADVANTAGES-

• Not as quick as ATP/PC system 
• Produces lactic acid ( fatiguing by-product)
• Reduced pH , inhibits enzymes 
• Stimulates pain receptors 

ADVANTAGES 

• Large glycogen and FFA stores avaliable 
• Efficient ATP resynthesis with O2 
• 38 ATP 1 glucose 
• low intensity high duration exercise 
• No fatiguing by-products 

DISADVANTAGES-

• Slower resynthesis 
• Requires more O2 
• More complex reactions 
• Delay of resynthesis as O2 required