Question on VO2 Max (Read 540 times)

When I look at my workouts and then click to see a summary of a particular run, it has "Statistics" and then it will have the amount of calories I burned and then "VO2 Max" with a number beside it. Can anyone explain what this means to me? Since it's automatically giving me the number I'd like to know what the number means and how to use that info. Thx, -R