How does the buildup of lactic acid in muscle cells result in more oxygen being delivered to your cells?

Lactic acid is created by our body when we can't breathe fast enough to get enough oxygen. For example, after running a while your muscles might start hurting, and that would be the lactic acid buildup because you couldn't get enough oxygen to keep you going. The reason the lactic acid buildup results in more oxygen is because you need oxygen to get rid of the lactic acid.