Why is quick anaerobic system and long anaerobic system does not produce lactic acid and why medium anaerobic system does produce lactic acid?

The quick anaerobic system, utilized during very short bursts of intense activity, primarily relies on phosphocreatine and does not produce lactic acid because it doesn't involve glycolysis. The long anaerobic system, used for extended high-intensity efforts, also avoids lactic acid production by utilizing oxygen for energy through aerobic pathways. In contrast, the medium anaerobic system operates in the glycolytic pathway, where glucose is broken down without oxygen, leading to the accumulation of lactic acid as a byproduct during sustained activities.