After undergoing strenuous exercise we feel pain in muscles, does adequate oxygen reach the muscles ?

Explanation

(1)We obtain energy by aerobic respiration.
(2)But an aerobic respiration can sometimes take place in our muscles.
(3)During vigorous exercise oxygen gets used up faster in the muscle cells that can be supplied by the blood.
(4)When anaerobic respiration takes place in human muscles, glucose is converted into lactic acid with the release of a small amount of energy.
(5)This results in the formation of lactic acid .
(6)The accumulation of lactic acid in the muscles causes muscular pains or cramps.