Heydenreich, Juliane, Yves Schutz, Bengt Kayser, and Katarina Melzer. “Validity of the Actiheart Step Test for the Estimation of Maximum Oxygen Consumption in Endurance Athletes and Healthy Controls”. Current Issues in Sport Science (CISS) 4 (March 12, 2019): 003. Accessed August 17, 2022. https://ciss-journal.org/article/view/7596.