Inter-laboratory reliability of VOb2smax and submaximal measurements

The purpose of this was to determine inter-laboratory variability for maximal and submaximal oxygen uptake (VO2) measurements. Subjects (n=8) performed three submaximal treadmill trials (five minutes each at 3 mph and 5.5 mph) and three maximal treadmill tests at three separate laboratories using SensorMedics 2900 Metabolic Carts. A standardized maximal incremental protocol was used for all subjects. A minimum time of 48 hours between tests was required and all tests for each subject were performed within two weeks. Each subject was scheduled at the same time of day for all three tests. The R values from the submaximal running were found to be significantly different between laboratories (p<0.05). Otherwise, no significant differences in metabolic measurements were found with submaximal walking and running (p<0.05). Based on the comparison of the means, most variables were stable between the laboratories. However, the mean (±SD) VO2max for laboratory A was 6.2 and 6.9 ml.kg-1.min-1 higher than the values for laboratories B and C, respectively (p<0.05). In addition, the mean (±SD) value for the C.V. for VO2max was 8.6±2.8% with a range of 2.5-11.3%. In conclusion, although most submaximal and maximal values were stable between laboratories, caution should be taken in making inter-laboratory comparisons of VO2max measures.