Answer:
Because of anaerobic energy production lactate accumulates in muscles, increases acidity and cause burning sensation.
Explanation:
If someone performs excessive exercise, needs more oxygen for muscles to work. In scarcity of oxygen muscles generates energy anaerobically from glucose.
In plenty of oxygen cells undergo aerobic pathway and produce much energy comparison to anaerobic pathway. When oxygen is not present or limited then pyruvate converts into lactate and accumulate in the muscle . Production of lactic acid in anaerobic condition; LACTIC ACID FERMENTATION cause burning sensation.