Development of a New Submaximal Walk Test to Predict Maximal Oxygen Consumption in Healthy Adults

The aim of the study was to develop a simple submaximal walk test protocol and equation using heart rate (HR) response variables to predict maximal oxygen consumption (VO₂max). A total of 60 healthy adults were recruited to test the validity of 3 min walk tests (3MWT). VO₂max and HR responses during the 3MWTs were measured. Multiple regression analysis was used to develop prediction equations. As a result, HR response variables including resting HR and HR during walking and recovery at two different cadences were significantly correlated with VO₂max. The equations developed using multiple regression analyses were able to predict VO₂max values (r = 0.75-0.84; r² = 0.57-0.70; standard error of estimate (SEE) = 4.80-5.25 mL/kg/min). The equation that predicted VO₂max the best was at the cadence of 120 steps per minute, which included sex; age; height; weight; body mass index; resting HR; HR at 1 min, 2 min and 3 min; HR recovery at 1 min and 2 min; and other HR variables calculated based on these measured HR variables (r = 0.84; r² = 0.70; SEE = 4.80 mL/kg/min). In conclusion, the 3MWT developed in this study is a safe and practical submaximal exercise protocol for healthy adults to predict VO₂max accurately, even compared to the well-established submaximal exercise protocols, and merits further investigation.