Gluconeogenesis from lactate is particularly important during periods of intense physical activity. As discussed before, when oxygen supply is insufficient, typically during intense muscular activity, pyruvate generated during glycolysis is converted into lactic acid by lactate dehydrogenase. Instead of accumulating inside the muscle cells, lactate produced by anaerobic fermentation is taken up by the liver. This initiates the other half of the Cori cycle. In the liver, gluconeogenesis occurs.
So glycolysis in the muscle and gluconeogenesis in the liver would seem to be cyclic (see image below). In fact, this apparent cycle was recognized by Carl and Gerti Cori, who shared the 1947 Nobel Prize for Medicine or Physiology with Bernardo Houssay for discovering how glycogen is broken down to pyruvate in muscle (in fact most) cells, which can then be used to resynthesize glucose in liver cells. Named after the Coris, The Cori Cycle, shown below, recognizes the interdependence of liver and muscle in glucose breakdown and resynthesis. Glucose generated in the liver can enter the bloodstream and be used in the muscle to support the physical activity.
Cori cycle on Wikipedia. Retrieved Sept. 26, 2020.