Final answer:
VO₂ max is the peak oxygen consumption rate during intense exercise, indicating aerobic capacity and cardiovascular fitness.
Step-by-step explanation:
VO₂ max or Maximal Oxygen Uptake is the maximum rate at which an individual can use oxygen during intense or maximum exercise. It is commonly used as an indicator of a person's aerobic capacity and cardiovascular fitness. The metabolic rate refers to how quickly the body converts food energy into another form, and this process requires oxygen. By measuring oxygen consumption, we can estimate energy consumption during various activities, as approximately 20 kilojoules (kJ) of energy are produced for every liter of oxygen consumed.
The respiratory quotient (RQ) is another important measurement, which indicates the ratio of carbon dioxide produced to oxygen consumed, giving insight into which type of fuel the body is using during metabolism. Furthermore, during exercise, the heart rate (HR) and stroke volume (SV) increase, which raises the cardiac output (CO) significantly, indicating improved cardiovascular fitness in well-trained athletes.