Answer: a. begins to accumulate significantly at a point that is about 55-65% of Vo2 max
Step-by-step explanation:
Lactate is produced in the body after the burning of glucose (glycolysis), to supply energy without the presence of oxygen (lactic anaerobic metabolism). In long-term physical activities, oxygen supply is not always sufficient. The organism seeks this energy in alternative sources, producing lactate. For the average human, blood lactate begins to accumulate significantly at a point that is about 55-65% of Vo2 max. The accumulation of this substance in the muscles can generate a hyperacidity, which causes pain and discomfort soon after exercise. Thus, the determination of lactate blood concentration allows indirect evaluation of the metabolic acidosis of the exercise, being one of the diagnostic tools used by Exercise Physiology.