VO2max

V̇O₂max is the maximum (max) volume (V) of oxygen (O₂) you can use during exercise. Measuring V̇O₂max requires specialist equipment, but there are many locations with the facilities and the cost is usually under $100. The procedure involves running on a treadmill while wearing a mask to capture your breath. There is a warm up period, and then you run at a reasonably stressful pace while the treadmill gradient is steadily increased until you can't keep going. For most of the test, as the workload increases so does the O₂ you use. However, there will come a point where the increased workload does not have a corresponding increase in O₂ usage. This is the point where you are using as much O₂ as you are capable of and you the increased workload is coming from anaerobic systems. While V̇O₂max is interesting, it does not include details of Running Economy, so it does not give a complete picture of a runner's capabilities. Arguably, VDOT is a more useful measure of fitness.