Lactic acid system
Anaerobic glycolysis. – this is the partial breakdown of glycogen. As no oxygen is present, the system stops with the production of lactic acid.
Description of process:
Glycogen to (GPP)
Glucose to (PFK)
Pyruvic acid to (LDH)
Lactic acid.
Aerobic/anaerobic - anaerobic
Intensity - high
Duration – 10 – 180 secs
Number ofATP resynthesised - 2
Where reaction takes place -sarcoplasm
Fuel used – glycogen/glucose
Enzyme(S) – GPP/PFK/LDH
By-product(s) – lactic acid/low pH
Sporting example – 400m sprint
Advantages of system
Large stores of glycogen in muscles and liver
2 ATP resynthesised (more than PC system – 1ATP)
Relatively quick energy provision – quicker than aerobic system
Provides energy for high intensity activity for up to 3 mins
GPP/PFK kick start system automatically, having detected decrease in PC
Disadvantages of system
Not as quick as the ATP/PC system
Causes pain and muscle fatigue
Produces lactic acid (fatiguing by-product)
Lowers pH (acidity) which inhibits enzyme action
Causes pain (stimulates pain receptors)
Training adaptations
Increases tolerance of lactic acid – lactate buffering
Increases stores of glycogen
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