Final answer:
A pulse oximeter, which measures blood oxygen levels, can give an indication of an individual's expected performance before an exercise test by revealing their metabolic rate and level of athletic conditioning.
Step-by-step explanation:
An easy to use and relatively accurate tool that could be used before an exercise test to give some indication of expected performance is a pulse oximeter. This device measures the amount of oxygen in the blood, providing insights into a person's metabolic rate, which is correlated with athletic conditioning and could indicate potential medical issues. Moreover, measurements relating to body pressures can serve as valuable medical indicators and analyses have shown consistency between different criteria.
Before an exercise test, professionals might also estimate expected performance based on existing knowledge and understanding of a person's conditioning. However, pulse oximetry serves as a simple, non-invasive, and effective method for preliminary assessment. It indicates the metabolic rate by showing the rate at which food energy is being converted, which can indirectly reflect a person's fitness level and possible functional capacity during an upcoming exercise test.
Additionally, measuring energy consumption in watts and oxygen consumption in liters O₂/min can further assist in predicting expected physical performance. Understanding these figures, along with other physiological variables, allows for the evaluation of an individual's power rating and physical capabilities.