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Lecture Notes

To overcome some of the cons of directly measuring VO2 max through a graded exercise test, sometimes we use submaximal exercise tests to indirectly measure VO2 max. Again, these tests would require a very similar set up with a metabolic cart, the person breathing in and out through a tube connected to that cart. They could be using a treadmill or a cycle ergometer for this test, and what this test really does is takes a person to, for example, maybe a predetermined heart rate, some level that is below their maximum level of effort, and then assumes a linear relationship between the person's heart rate and their work rate. So you can see in the figure on the right, you have heart rate on the y-axis, work rate on the x-axis, and the first three points that are connected by solid lines are points that were derived from someone's actual data on a submaximal exercise test. The rest of that line is dotted because it's an extrapolated line, assuming that the relationship is going to stay the same as that work rate increases. And it's essentially using an equation to estimate what someone's maximal oxygen consumption would be, without having to take the person to a maximal effort or exertion.