Can VO_2max be accurately estimated using exercise-duration based prediction equations and a nomogram?

Study aim: The purpose of this study was to examine a large cohort of young Canadian adults to determine if exercise time from a maximal Bruce Treadmill Protocol could accurately predict measured VO_2max values by inputting the total exercise time into prediction equations and a nomogram.

Materials and methods: 550 kinesiology undergraduate student (280 male and 270 female) participants, with a mean body mass (BM) of 72.08 ± 15.05 kg, mean age of 21.16 ± 1.26 years old and mean height of 171.95 ± 10.25 cm completed a maximal graded exercise test to obtain their VO_2max (measured). Predicted VO_2max was calculated with various equations using the variable of total exercise test time. Linear regression models were created to determine how well the predicted VO2max values compared to the measured values.

Results: Across all VO_2max calculation methods, males obtained higher VO2max values on both the measured (49.89 ± 9.21 mL/ kg/min) and predicted values (46.04–55.40 mL/kg/min) and exercised for a longer duration of time (14.33 minutes) compared to females (40.89 ± 7.50 mL/kg/min, 38.87–48.36 mL/kg/min, 11.92 minutes). Classifications and percentile rankings were created using each measured and predicted method.

Conclusions: The Healthy Persons Equation [6], Healthy Men and Women Equation [2], Active and Sedentary Women/Men Equations [10, 22] and nomogram [13] cannot accurately predict VO_2max in healthy young adults, with R² values between 0.38–0.50. The Healthy Persons Equation [6] was found to very closely mimic the seven-category classifications determined from the measured CPET VO2max values.