The maximal rate of O₂ consumption (VO₂ max) constitutes one of the oldest fitness indexes established for the measure of cardiorespiratory fitness and aerobic performance. Procedures have been developed in which VO₂ max is estimated from physiological responses during submaximal exercise. Generally, VO₂ max is estimated using the classical renowned Astrand-Ryhming test. In young adults, poor fitness and low aerobic performance are often associated with a sedentary lifestyle, which is a well-described factor for the development of obesity and its related disorders such as cardiovascular diseases and type 2 diabetes. In the Indian Ocean, the inhabitants of La Reunion Island, a French overseas department, exhibit an increasing prevalence of obesity and type 2 diabetes. At the University of La Reunion, a new laboratory course involving students was designed to teach the indirect evaluation of their VO₂ max from the classical Astrand-Ryhming test and using a cycle ergometer as the exercise mode. Inverse and significant correlations were established between the students' fat mass percentages and their VO₂ max and between their waist-to-hip ratio and VO₂ max as well. Results from the international physical activity questionnaire showed that most participants in this laboratory were sedentary students. Therefore, this laboratory makes the students practice and understand the use of a classical test to estimate their VO₂ max. It also alerts them to the correlation between a sedentary lifestyle and higher body fat content. This exercise allowed students to use a scientific method to engage the problem of sedentary lifestyle, which is a real world issue.