Measuring V̇O2 and V̇CO2 during exercise allows calculation of total energy expenditure and the ratio of fat to glycolytic oxidation.

“these numbers fit into a relative atively straightforward linear equation called the wear equation and it tells you three things it tells you total energy consumption in uh kilo calories per minute and then the ratio of V2 and vco2 tell you how much of that energy is coming from fat oxidation and how much of it is glycolytic yeah so at any moment in time you can look at a vco2 and a V2 which are usually measured in liters per minute and you can convert that into a total GRS of fat oxidation in a total grams of glucose oxidation per minute”