There are many valid tests that are used in a laboratory setting to assess an individual’s level of fitness. Fitness tests are categorized by what they are attempting to measure such as body composition, aerobic endurance, and muscular strength.
Body composition refers to the relative percentage of body weight that is fat versus fat-free tissue, or more commonly known as “Percent Body Fat.” Underwater weighing is the most common technique used in exercise physiology laboratories to determine body composition. This method involves the use of an underwater weighing tank, where the individual being tested sits in a tank that is nearly filled with water. The individual exhales all of their air out and then bends forward until the top of his or her head is underwater, remaining motionless for 5-10 seconds so that the tank’s scale can determine the correct weight.
In a laboratory setting, an individual’s aerobic endurance is often measured when an individual performs activity on a treadmill or bicycle, while wearing special equipment that covers the mouth and nose. This equipment has the ability to measure the amount of oxygen you inhale and the amount of carbon dioxide you exhale. During the test, an individual gradually increases their workload (or intensity of the exercise) until their maximal heart rate is reached or until they become exhausted, as indicated by the Health and Fitness Professional conducting the test.
To measure muscular strength, some university laboratories use large, bulky, and expensive electronic equipment that isolates body movement so that the individual being tested lifts a specific amount of weight for the entire duration of the movement. This type of equipment are often used to perform research and for injury rehabilitation within physical therapy clinics.