Chapter 4

Lecture Notes

Oftentimes what you'll see is that direct measures of cardiorespiratory fitness, or VO2 max, are difficult to administer, expensive, time consuming, they require special equipment, and so because of that, many of these indirectly measured tests have been developed. Maximal graded exercise tests allow us to measure cardiorespiratory fitness or VO2 max directly, and these tests are really the gold standard, or the best way for measuring cardiorespiratory fitness. As you can see from the two pictures, there are multiple different ways that you can conduct this test. The picture on the top shows a young woman connected to a metabolic cart that's collecting all of her expired air, but she's on a cycle ergometer. The woman on the bottom is running on a treadmill, again connected through a very similar system that's collecting her expired air. Regardless of the type of activity that you use here, this test requires the person to work to exhaustion while the test is continuously increasing intensity, and the peak of the test, or the end of the test to determine cardiorespiratory fitness, or VO2 max, is when the intensity increases—so, for example, on the treadmill, you could increase intensity by increasing speed and/or the incline, usually both—when that intensity increases and the consumption of oxygen from the person levels off, or alternatively the participant always has the option of ending the test when they feel they can no longer go any further. So the good things about this test are that it's accurate, it's sensitive enough to detect clinical issues—so, for example, these tests are sometimes used to detect coronary artery disease in individuals who are asymptomatic who don't present with any symptoms at all. The cons are that it can be very expensive, potentially high-risk because you're taking people to maximal state of exercise, and you need special equipment like the metabolic carts that are featured here in the pictures.