How is fitness measured in the lab?

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.

One of the most economical and efficient methods to measure your fitness level is by using a heart rate monitor and a baseline workout.

A baseline workout can be completed in any activity that the physically active person wants. It consists of a workout that can be repeated consistently from one month to the next. The most important aspect of the workout is that it has to be repeatable with the same environment, route, pace, time of day, day of the week, etc. The only variable is the heart rate level. If the fitness level is improving, a physically active person should be able to reduce the heart rate level month after month during the baseline workout. If the fitness level is not improving then the heart rate level will not be reduced.

A favorite baseline workout consists of using a treadmill. By using the same workout facility, the environment is consistent in temperature and humidity.  Use the same brand of treadmill with the incline and speed set the same. Wear the same level of clothing, drink the same level of water, use it on the same day of the week, and at the same time of day. The only variable will be your heart rate.

The baseline workout should be completed in the optimum aerobic heart rate range. The range should be measured using a heart rate monitor. So, what is this optimum aerobic heart rate range and how can a physically active person determine his/her optimum aerobic heart rate range?

The optimum aerobic heart rate range is a range of approximately 10 beats per minute (BPM) where each person is getting the maximum fitness improvement without risking injury or long-term physical problems.
Eric Olsen
Fitness is generally measured in the lab as maximum oxygen uptake, or VO2 max. This is a measure of the body’s ability to take in and use oxygen. If you have a higher VO2 max, this means you use more oxygen, so you can perform more work before fatigue sets in.
Lifefit: An Effective Exercise Program for Optimal Health and a Longer Life

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Lifefit: An Effective Exercise Program for Optimal Health and a Longer Life

An easy-to-follow programme for lengthening and improving lives. More than an exercise guide, this text is an effective tool for making meaningful lifestyle decisions to benefit long-term fitness. In...

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.