BreakingJogging sport graphics down glucose to produce energy in the absence of oxygen

Repeated and frequent muscle contraction

 

BLOOD cannot supply enough oxygen

Muscles suffer from oxygen defieciency (oxygen debt)

Break down glucose into lactic acid 

HIGH concentration of lactic acid cause MUSCLE CRAMPS and FATIGUE

Breathing becomes rapid and deep to get more oxygen to oxidise the lactic acid into carbon dioxide and water in liver