VO2max

A graph showing that O₂ consumption increases with exercise intensity until a maximum is reached, which is V̇O₂max.

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 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.

1 V̇O₂max and vV̇O₂max

The velocity that is reached at V̇O₂max is called vV̇O₂max. An approximation of vV̇O₂max is the mile race pace, but a more accurate formula is shown below.

vV̇O2max = V̇O2max /3.5

Where V̇O₂max is in ml/Kg/min and vV̇O₂max is in km/hr.

2 V̇O₂max and V̇O₂peak

This graph shows that V̇O₂peak, which is the highest O₂ observed, without the plateau that defines V̇O₂max.

Some research uses the term V̇O₂peak rather than V̇O₂max, and while the two are similar, there is an important difference. Where V̇O₂max is the highest O₂ uptake seen, even though exercise intensity has continued to increase, V̇O₂peak is simply the highest O₂ seen. It's possible for V̇O₂peak to be the same as V̇O₂max, but only if the test is terminated at just the right point. The biggest problem with V̇O₂peak is that a training program might result in a subject getting better at the test, which would result in a higher V̇O₂peak value, without actually changing their V̇O₂max. For instance, I might have a V̇O₂max of 60, but find the testing protocol so hard that I give up when my V̇O₂ reaches 50 which would only give a V̇O₂peak value. If I do some high intensity training, I'd be more comfortable at these high workloads and I might reach a V̇O₂peak of 55, which would look like a 10% improvement, but is actually not a change in physical fitness.