A recent study by the University of Eastern Finland shows that scaling maximal oxygen uptake and maximal workload by body weight confounds measures of cardiorespiratory fitness. It has been a common practice in exercise testing to scale the results by body weight and, according to researchers, this practice should be abandoned. More reliable data on cardiorespiratory fitness can be observed by using lean mass proportional measures. The results were published recently in Clinical Physiology and Functional Imaging.
Exercise tests, such as the maximal cycle ergometer exercise test, are used to evaluate cardiorespiratory fitness. Maximal performance refers to an individual’s metabolic capacity. While the size of an individual is an important determinant of the maximal workload and maximal oxygen uptake, the absolute values should be scaled by body size or composition to enable comparison between individuals. Body weight has traditionally been used to perform body size related scaling in exercise testing.
Scaling methods, when measuring the function of the human body, have been causing scientific debate since the mid-1600s. Scaling by body weight has been criticized, because body fat, per se, does not increase metabolism during exercise.