Lactate Anaerobic Energy systems

Steps in the Anaerobic Glycolytic System

Glycogen is converted to glucose by the enzyme glycogen phosphorylase

Glucose is then broken down to pyruvic acid by enzyme phosphofructokinase → this is called anaerobic glycolysis

Pyruvic acid is then broken down by the enzyme lactate dehydrogenase into lactic acid

Lactic acid denatures the enzymes involved in respiration meaning the muscle cells become slower are re-synthesising ATP

Summary of Anaerobic Glycolytic System

• 2 molecules of ATP are produced from one molecule of glucose breakdown

• Takes place in sarcoplasm of muscle cell where there is no oxygen

• Because its an anaerobic process, the pyruvic acid is broken down into lactic acid

• The presence of oxygen is needed to break down lactic acid back into liver glycogen

What is OBLA?

Onset of Blood Lactate Accumulation

• Point at which lactate starts to accumulate in the muscle / blood / known as the lactate threshold

• Starts at 4 mmol / litre

• Occurs as body is unable to provide enough oxygen to break down lactic acid

Factors that affect OBLA

Intensity of exercise – higher intensity the faster OBLA occurs

VO2 max of a performer – higher the level the more delayed OBLA

Respiratory exchange ratio (RER) – closer the value to 1.00 quicker OBLA occurs

Muscle fibre type – if slow twitch fibres used, delays OBLA

What are the advantages of the Anaerobic Glycolytic system?

• ATP can be re-synthesised very quickly

• Lasts longer than ATP-PC systems

• In the presence of oxygen, lactic acid can be converted back into liver glycogen

• Can be used for a sprint finish

What are the disadvantages of the Anaerobic Glycolytic system?

• Lactic acid is the by-product, the acid denatures enzymes involved in respiration meaning the muscle cells become slower at resynthesizing ATP

• Can cause a lot of fatigue

• Only a small amount of energy can be released from glycogen (5%)