(Re)assessment of the COSMED Quark CPET and VO2Master Pro Systems for Measuring Pulmonary Gas Exchange and Ventilation
In this study Dr. Thiessen and his team assessed “the validity, reliability, and transferability of gas exchange and ventilatory variables from two commonly used metabolic measurement systems (COSMED Quark and VO2Master Pro).
Johan S. Thiessen, Nasimi A. Guluzade, Robin Faricier, Daniel A. Keir
Scandinavian Journal of Medicine & Science in Sports
January 29, 2025
Introduction
Metabolic testing with metabolic carts has traditionally been used is hospitals and labs internationally. Validation of accuracy of the newer portable units is essential as they are being used in unprecedented research environments as well as the fitness, wellness and athletic industries globally.
In this study Dr. Thiessen and his team assessed “the validity, reliability, and transferability of gas exchange and ventilatory variables from two commonly used metabolic measurement systems (COSMED Quark and VO2Master Pro).
Methods
Equipment and Experimental Setup
A metabolic simulator (VacuMed) was used to generate precise gas exchange and ventilatory conditions at four simulated exercise intensities: V̇O2 of 1.0, 2.0, 3.0, and 4.0 L/min with corresponding V̇E values of 30, 60, 105, and 150 L/min. Each system was tested in a randomized order, with three measurements per intensity on two separate days. Additionally, Douglas bag- based measurements were collected as a reference. The COSMED Quark CPET and VO2Master Pro devices were calibrated before each test. The COSMED Quark uses a bidirectional turbine and gas analyzers, while the VO2Master Pro employs a differential pressure flow sensor and an O2 analyzer. Both systems apply different standard temperature and pressure (STPD) correction factors, necessitating adjustments to ensure accurate comparisons.
Simulated and Human Experiments
In addition to simulated tests, human trials were conducted with five participants cycling at steady-state intensities (100W and 160W). Each participant completed five trials using each measurement system, including the Douglas bag, on separate days in a randomized order.
Validity
Both systems demonstrated a mean percent error below 3% for V̇O2 and V̇E, aligning with the acceptable range for metabolic testing equipment. The COSMED Quark had a mean error of 3.5% for V̇O2 and 2.0% for V̇E, while the VO2Master Pro exhibited a lower mean error of 0.6% for V̇O2 and 1.1% for V̇E. The Douglas bag method recorded percent errors of 1.5% to -3.7% across intensities.
Human Trials
Steady-state V̇O2 and V̇E values recorded during cycling at 100W and 160W were consistent across all devices. There were no statistically significant differences between measurement systems, reinforcing the transferability of simulator-based findings to human testing conditions.
Conclusion
“Using the VacuMed metabolic simulator to simulate human pulmonary gas exchange andventilation, we compared the expected values of V̇ E , B F , V T , V̇O 2 , and V̇CO 2 variables at four exercise “intensities” (1.0, 2.0, 3.0, and 4.0 L·min −1 ) with the measured values of two metabolic measurement systems (COSMED Quark CPET and VO2Master Pro). This study demonstrated that the error of V̇ E and V̇O 2 during simulated breathing is generally < 3% and is consistent between-days and between-devices within a simulated V̇O 2 range of 1–4 L·min −1 . Notably, the overall relative error of measured V̇O 2 for the VO2Master System averaged ±0.6% (SD of 3.0%), which is similar to reported error rates (± 1%) for the VacuMed simulator. Findings also indicate low variability concerning between-day accuracy for all four devices. Together, when in good operating condition and meticulously operated, both systems appear valid, reliable, and transferable and are, therefore, suitable for within-day, between-day, and between-device use in a laboratory setting.”
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