Clinical Exercise Physiology COMPARISON OF OXYGEN UPTAKE ON-KINETIC CALCULATIONS DURING SUBMAXIMAL EXERCISE

COMPARISON OF OXYGEN UPTAKE ON-KINETIC CALCULATIONS DURING SUBMAXIMAL EXERCISE. Ross Arena, Reed Humphrey, Mary Ann Peberdy, Michael Madigan. JEPonline. 2003;6(2):1-7. The mean response time (MRT) and time constant (TC) are two oxygen uptake (VO2) on-kinetic calculations whose values are presumed to be interchangeable. This study tests the assumption of uniformity among different VO2 on-kinetic calculations. Nineteen (13 male/6 female) apparently healthy subjects were recruited for this study. Mean age (±SD) for this group was 44.1±10.1 years. Subjects underwent a progressive exercise test and six-minute exercise session (1.6 m/hr, 3.0% grade) on separate days. Both breath-by-breath (bb) and 10-second averaged (avg) ventilatory expired gas data were used to produce four VO2 on-kinetic calculations (MRTbb, MRTavg, TCbb, TCavg). There were statistically significant differences (p<0.05) between TCbb (17.6 s) and TCavg (22.7 s), MRTbb (22.9 s), and MRTavg (24.7 s). Comparisons amongst TCavg (22.7 s), MRTbb (22.9 s), and MRTavg (24.7 s) did not reach statistical significance (p>0.05). All VO2 on-kinetic calculations were significantly correlated with peak VO2, age, and each other. These results indicate that all MRT and TC calculations may not be interchangeable. All VO2 uptake on-kinetic expressions did, however, appear to represent aerobic capacity and were highly correlated with each other indicating that calculation method may not have an excessively negative impact.