Slow and fast twitch fibres

• Slow twitch fibres

  Darker muscle found in legs and body

  For slower contraction ( long periods of exercise)

  Aerobic respiration
• Slow twitch fibres have lots of mitochondria and myoglobin
• Myoglobin

  Similar to haemoglobin

  Acts as an oxygen store
• Fast twitch fibres

  Pale muscles

  For rapid intense contractions

  ATP used

  Anaerobic respiration

  Few mitrochondria

  Few myoglobin