Which respiration is more efficient in human, anaerobic or aerobic? Why?

Aerobic respiration is more efficient than anaerobic respiration.

Explanation: Aerobic respiration is more efficient than anaerobic respiration because in aerobic respiration, the pyruvate produced by the breakdown of glucose in glycolysis is further oxidized to acetyl CoA which then enters the Krebs cycle to produce ATP, NADH and FADH2. NADH and FADH2 produced in Krebs cycle enters the electron transport chain where they are further oxidized to generate more ATP but in anaerobic respiration, pyruvate produced by glycolysis is either reduced to lactate via lactic acid fermentation under low-oxygen conditions or converted to ethanol and water via alcoholic fermentation in low-oxygen or anaerobic fermentation. Lactate and ethanol produced via fermentation can not be oxidized further in Krebs cycle and electron transport chain to generate more ATP.