Accuracy of respiratory gas variables, substrate, and energy use from 15 CPET systems during simulated and human exercise

Abstract

PurposeVarious systems are available for cardiopulmonary exercise testing (CPET), but their accuracy remains largely unexplored. We evaluate the accuracy of 15 popular CPET systems to assess respiratory variables, substrate use, and energy expenditure during simulated exercise. Cross‐comparisons were also performed during human cycling experiments (i.e., verification of simulation findings), and between‐session reliability was assessed for a subset of systems.MethodsA metabolic simulator was used to simulate breath‐by‐breath gas exchange, and the values measured by each system (minute ventilation [V̇E], breathing frequency [BF], oxygen uptake [V̇O2], carbon dioxide production [V̇CO2], respiratory exchange ratio [RER], energy from carbs and fats, and total energy expenditure) were compared to the simulated values to assess the accuracy. The following manufacturers (system) were assessed: COSMED (Quark CPET, K5), Cortex (MetaLyzer 3B, MetaMax 3B), Vyaire (Vyntus CPX, Oxycon Pro), Maastricht Instruments (Omnical), MGC Diagnostics (Ergocard Clinical, Ergocard Pro, Ultima), Ganshorn/Schiller (PowerCube Ergo), Geratherm (Ergostik), VO2master (VO2masterPro), PNOĒ (PNOĒ), and Calibre Biometrics (Calibre).ResultsAbsolute percentage errors during the simulations ranged from 1.15%–50.3% for V̇E, 1.05–3.79% for BF, 1.10%–17.5% for V̇O2, 1.07%–18.3% for V̇CO2, 0.62%–14.8% for RER, 5.52%–99.0% for Kcal from carbs, 5.13%–133% for Kcal from fats, and 0.59%–12.1% for total energy expenditure. Between‐session variation ranged from 0.86%–22.4% for V̇O2 and 1.14%–20.2% for V̇CO2, respectively.ConclusionThe error of respiratory gas variables, substrate, and energy use differed substantially between systems, with only a few systems demonstrating a consistent acceptable error. We extensively discuss the implications of our findings for clinicians, researchers and other CPET users.

Changes in running economy and running technique following 6 months of running with and without wearable‐based real‐time feedback

“…The mask was connected to a T‐piece that was placed in a free airstream (200 L min −1 ). Respiratory gases were captured using a total‐capture indirect calorimeter (Omnical, Maastricht Instruments, Maastricht, the Netherlands) 35 to investigate running economy at each speed. The system was calibrated automatically every 15–30 min using room air and a gas mixture of known composition.…”

Differences in running technique between runners with better and poorer running economy and lower and higher milage: An artificial neural network approach

“…The mask was connected to a T‐piece that was placed in a free airstream (200 L min −1 ). Respiratory gasses were captured using a total‐capture indirect calorimeter (Omnical, Maastricht Instruments, Maastricht, The Netherlands) 28 . The system was calibrated automatically every 15–30 min using room air and a gas mixture of known composition.…”

“…Respiratory gasses were captured using a total-capture indirect calorimeter (Omnical, Maastricht Instruments, Maastricht, The Netherlands). 28 The system was calibrated automatically every 15-30 min using room air and a gas mixture of known composition. Laboratory temperature was kept constant at 18°C-21°C and relative humidity of 50%-55% during all test sessions.…”

Editor highlights: Assessment of commercially available metabolic carts, physical activity to boost brain performance, and training prepubertal children

“…In the first issue of the 34th volume of the Scandinavian Journal of Medicine & Science in Sports (SJMSS), a comprehensive comparative analysis of performance accuracy and reliability of 15 widely used and commercially available metabolic carts (CPET) is presented. 1 Remarkably, only a few of these devices meet the accuracy and reliability standards for research and clinical evaluation. The insights provided here will be invaluable for researchers making informed choices about the most suitable metabolic cart for their experimental setups.…”

“…In turn, a precise measurement of RER is fundamental to assess resting energy expenditure, energy efficiency during exercise, or maximal fat oxidation. In the first issue of the 34th volume of the Scandinavian Journal of Medicine & Science in Sports (SJMSS), a comprehensive comparative analysis of performance accuracy and reliability of 15 widely used and commercially available metabolic carts (CPET) is presented 1 . Remarkably, only a few of these devices meet the accuracy and reliability standards for research and clinical evaluation.…”