The measured vs. estimated oxygen uptake from treadmill exercise testing in patients with chronic pulmonary diseases

Oxygen uptake (VO2) estimated from treadmill workload is often used in clinical practice, but the equation of American College of Sport Medicine (ACSM) was not obtained experimentally so this estimation can be very misleading. The objective of this study was to compare the estimated VO2with the measured VO2 in patients with chronic lung diseases and whether exercise training can be prescribed basing on estimated values of VO2. Methods: 42 patients with chronic pulmonary diseases (34 male; aged 61.2±10.7; FEV1 - 58.1±14% predicted) performed cardiopulmonary exercise testing on treadmill. The estimated VO2 was calculated using the adapted equation of ACSM: (VO2 [ml/kg/min] = 1.67*km/h+0.3006*%*km/h+3.5) from the last completed stage. Statistical analysis was performed with Bland-Altman method and linear regression. Results: The estimated and measured VO2 were 18.34±6.67 and 14.57±4.65 ml/kg/min, respectively. The mean difference between the estimated and measured VO2 was 3.77 ml/kg/min (p Conclusions: In most cases the estimated VO2 is more than measured VO2. The mean difference between the estimated and measured VO2 was more than 1 MET (3.77 ml/kg/min). The estimated VO2 for assessment of “true” VO2 should be used with caution. It is necessary to develop an accurate formula to calculate VO2 for treadmill test.