Question

Describe the reasons why acute altitude exposure causes one to produce more lactate for any specific workload.

Answer 1

Air gets thinner as we go upwards in the atmosphere (troposphere). So, at higher altitudes O₂ availability reduces gradually. When a person performs any work at high altitude (low oxygen availability) then body needs more oxygen and in order to fulfill that need the breathing becomes frequent (Panting). But even after increase in breathing rate the amount of available oxygen to the tissues may not suffice (due to sudden increase in altitude the body does not get enough time to increase the hemoglobin content or number of RBC). Therefore, the cells will be forced to perform anaerobic respiration and krebs cycle and oxidative phosphorylation will be stopped temporarily. The body cells will solely depend upon glycolysis for it's energy needs. For glycolysis to remain operative. regeneration of NAD+ from NADH is very necessary. This regeneration happens by lactic acid production. Lactate dehydrogenase converts the end product of glycolysis (pyruvate) to lactate with simultaneous conversion of NADH to NAD+. More round of glycolysis will cause more accumulation of lactate.