Proposed shorter duration protocols for measuring exercise energetics utilizing whole room indirect calorimetry

Previously, 30 min is the shortest testing duration that is validated for exercise energetics (EXEE; kcal) in human subjects utilizing a whole room indirect calorimeter (WRIC). The objective of this analysis was to show the validity of extrapolating 30-min EXEE from the first 15 min of moderate intensity steady state cycling in human subjects utilizing a WRIC. Metabolic data from human subjects that had 30-min EXEE measured within a WRIC (10,000 L), along with simulated EXEE of the same duration determined by propane combustion, were utilized for this analysis. Metabolic data for 30 min of oxygen consumption (VO₂; liters), carbon dioxide production (VCO₂; liters), the respiratory quotient (RQ; VCO₂/VO₂) and EXEE (kcal), were calculated. Thereafter, the first 15 min of data from both actual and simulated metabolic measurements from human subjects and propane combustion, respectively, were utilized to extrapolate 30-min VO₂, VCO₂, RQ and EXEE. Statistical (p < 0.05) comparisons between actual and extrapolated metabolic parameters were determined by SPSS (version 30). No significant differences existed between actual and extrapolated metabolic parameters for both human subjects and that from propane combustion. In conclusion, utilizing the first 15 min of steady state cycling exercise data to reflect a 30-min measurement duration is valid.