ASSESSING CARDIORESPIRATORY FITNESS
The body’s ability to maintain a level of exertion (exercise) for an extended time is a direct reflection of cardiorespiratory fitness. One’s level of fitness is determined by the body’s ability to take up, distribute, and use oxygen during physical
activity. As explained earlier, the best quantitative measure of cardiorespiratory endurance is maximal oxygen consumption, expressed as VO2max, the amount of oxygen the body uses when a person reaches his or her maximum ability to supply oxygen during exercise. Maximal oxygen consumption can be measured precisely in an exercise physiology laboratory through analysis of the air a person inhales and exhales when exercising to a level of exhaustion (maximum intensity). This procedure can be expensive and time-consuming, however, making it impractical for the average person.
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Choosing an Assessment Test
Fortunately, several simple assessment tests provide reasonably good estimates of maximal oxygen consumption (within 10-15% of the results of a laboratory test). Four commonly used assessments are the following:
• The 1-Mile Walk Test. This test measures the amount of time it takes you to complete 1 mile of brisk walking and your heart rate at the end of your walk. A fast time and a low heart rate indicate a high level of cardiorespiratory endurance.
• The 3-Minute Step Test. In the step test, you step continually at a steady rate for 3 minutes and then monitor your heart rate during recovery. The rate at which the pulse returns to normal is a good measure of cardiorespiratory capacity; heart rate remains lower and recovers faster in people who are more physically fit.
• The 1.5-Mile Run-Walk Test. Oxygen consumption increases with speed in distance running, so a fast time on this test indicates high maximal oxygen consumption.
• The Beep Test. This test predicting maximal oxygen consumption is excellent for people who are physically fit and wish to measure their capacity for high-intensity exercise, such as sprints. A prerecorded series of “beeps” (tones) sound off at faster and faster intervals. Your task is to keep up with the beeps during the exercise. Lab 3.1 provides detailed instructions for each of these tests.
An additional assessment, the 12-Minute Swim Test, is also provided. To assess yourself, choose one of these methods based on your access to equipment, your current physical condition, and your own preference.
Don’t take any of these tests without checking with your physician if you are ill or have any of the risk factors for exercise discussed in Chapter 2 and Lab 2.1.