The Validity of the YMCA 3-Minute Step Test for Estimating Maximal Oxygen Uptake in Healthy Korean and Vietnamese Adults.

Background: Cardiorespiratory fitness (CRF) is a fundamental component of physical fitness. While maximal oxygen uptake (VO₂max) is the gold standard for quantifying CRF, standard maximal exercise tests using direct measurements VO₂max are dependent on the availability of laboratory equipment, and thereby expensive and time consuming. Recently, an equation was formulated to indirectly estimate VO₂max using the YMCA 3-minute step test.

Methods: The study included 15 Korean (KR) and 15 Vietnamese (VN) healthy adults aged 19-35 years. All subjects completed a YMCA 3-minute step test (YMCA 3MST) and a maximal exercise treadmill test to predict VO₂max and VO₂max measures, respectively.

Results: There was a significant relationship between VO₂max predicted from the YMCA 3MST and actual VO₂max measurements from the treadmill test (r = 0.80, p < 0.0001; KR group: r = 0.81, p < 0.0001; VN group: r = 0.93, p < 0.0001). Bland-Altman analysis revealed statistical agreement between tests, although there was a systematic overestimation of 3.36 mL/kg/min for the KR group.

Conclusion: The equation for predicting VO₂max from the YMCA 3MST was validated among the study subjects. However, future research should explore the validity and reliability of the YMCA 3MST equation for estimating VO₂max in other populations.