The maximal rate of O[subscript 2] consumption (VO[subscript 2max]) constitutes one of the oldest fitness indexes established for the measure of cardiorespiratory fitness and aerobic performance. Procedures have been developed in which VO[subscript 2max]is estimated from physiological responses during submaximal exercise. Generally, VO[subscript 2max]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 VO[subscript 2max]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 VO[subscript 2max]and between their waist-to-hip ratio and VO[subscript 2max]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 VO[subscript 2max]. 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. (Contains 7 figures.)