We have the HIF-pathway to measure the oxygen level in the cell. If oxygen levels are too low, aerobic dissimilation is suppressed (and modified). (a bit controversial but as far as I understand:) the anaerobic reaction/dissimilation always happens. It occurs near the cell wall. At the mitochondria (between the double walls) lactate is reverted back to pyruvate and the pyruvate can enter the mitochondria inner lumen for aerobic dissimilation. The HIF-pathway can (indirectly) suppress and modify this process. If lactate is no longer used by the mitochondria the concentration of lactate in the cell increases and the lactate flow out of the cell increases.