effects of short duration/high intensity exercise

• describe lactate accumulation


  - when lactic acid is produced as a result of glycolysis during high intensity exercise, hydrogen ions are released

  - as lactate accumulates in the muscles, so do the hydrogen ions, increasing the ACIDITY

  - this increase in acidity slows down the ENZYME ACTIVITY which prevents the breakdown of glucose which causes muscle fatigue
• define V02 max


  maximum volume of oxygen that can be used by working muscles per minute
• define lactate threshold


  point at which lactic acid rapidly accumulates in the blood
• define OBLA


  onset of blood lactate accumulation - point at which lactate levels go above 4 millimoles/litre
• factors affecting lactate accumulation

  - INTENSITY OF EXERCISE - higher intensity the faster lactate accumulation occurs

  - FITNESS OF PERFORMER - As a result of training adaptations ( more mitochondria, greater capillary density ) fitter performers can delay OBLA

  - V02 MAX OF A PERFORMER/ BUFFERING CAPACITY - performers with a higher V02 max have a delayed rate of lactate accumulation

  - RESPIRATORY EXCHANGE RATIO ( RER ) - a RER closer to 1.00 leads to quicker lactate accumulation

  - MUSCLE FIBRE TYPE USED - if slow twitch fibres used, lactate accumulation is delayed
• describe lactate threshold and OBLA in different performers

  - the higher a performers V02 max, higher the lactate threshold, so lactic acid build up delayed ( mainly aerobic performers )

  - average performers have lower LT than elite

  - elite power athletes have much better anaerobic endurance than non-elite performers as bodies have adapted to cope with higher levels of lactate

  - elite increase rate of lactate removal through process of buffering

  - trained athletes can exercise for much longer, at higher intensities than untrained individuals, as their LT occurs at a much higher % of their V02 max ( and higher OBLA )
• what is lactate threshold expressed as

  expressed as a % of V02 max