Comparison of the VO₂ Master Pro and Cosmed K5 During Walking, Jogging, and Running

Portable devices that accurately detect the composition of expired gases and changes in VO₂ open new possibilities in research methodology and accessibility.

The purpose of this study was to compare the oxygen consumption (VO₂) measurements of the VO₂ Master Pro (VM) to the Cosmed K5 (K5) during walking, jogging, and running in field and lab conditions.

Twelve proficient runners, with a current 10 k pace of ≥ 11.29 km/h, performed 3 matched intervals at 3 different speeds (4.82, 8.05, 11.29 km/h) on a treadmill and on an outdoor track. An airflow test was also performed on both devices by pumping air through the devices using a 3 L syringe timed to a metronome at 15, 25, and 35 beats/min.

The VM did not report walking data for most participants. During treadmill running, there were significant differences in VO₂ (47.86 ± 3.94 vs. 29.56 ± 4.15 mL/kg/min), ventilation (V_e) (71 vs. 57 mL/min), and tidal volume (TV) (1.89 vs. 1.56 L) between the K5 and VM respectively (P < 0.05). Outdoor analysis also showed significant differences between devices in VO₂, V_e, and TV (P < 0.05). The airflow test showed significant differences between the devices in V_e and TV (P < 0.05).

These results suggest that there are significant discrepancies between the K5 and the VM, likely due to differences in TV measurement.