Question

(a) How does VO2max define subject's aerobic capacity?

(b) Why is VO2 a measure of cardiovascular fitness?

Answer 1

a) VO₂ max is the maximum volume of oxygen a person can utilise during exercise.

this is actually measured using the graded exercise test. we ask the subject to do a treadmill test in which exercise intensity is progressively increased. then we measure the oxygen consumption of the individual. at a particular exercise intensity, the maximum utilisation of oxygen is noted. till this point of exercise takes place mainly by aerobic glycolysis.

further increase in exercise intensity, oxygen consumption remains constant and extra energy needed for the exercise comes from anaerobic glycolysis.

so if VO₂ max is more, more oxygen the subject can utilise, and the subject can do more exercise by aerobic pathway.

b) VO₂  is a measure of cardio-respiratory fitness

if a person uses have more VO2 max means- his respiratory and circulatory fitness is good.

oxygen first is diffused to the pulmonary circulation from the alveoli of the lungs, it is then circulated to the tissue with the help of cardiovascular system and it is utilised by the tissue using aerobic glycolysis.

if there is any lung disease or cardiovascular disease or any toxins which block aerobic pathway-   the VO2 max will be less and the patient will be less fit and will have less exercise tolerance.