What is Vo2 max?
Maximal oxygen uptake (Vo2 max) is the maximal amount of oxygen consumed by the body during an exhaustive exercise such as cycling or running (1)
What does it actually means?
As you continue to exercise, you'll exhale less oxygen (because the oxygen will be utilized by cells). Hence this will cause your Vo2 number to rise. When this number plateaus, you've reached Vo2 max (2). In general people with high Vo2 max can exercise or perform at higher intensity without getting fatigued. This test is a gold standard test to assess your aerobic capacity (2).