A new equation to predict peak VO2 in obese patients during cardiopulmonary exercise testing

Clin Physiol Funct Imaging. 2018 May;38(3):462-467. doi: 10.1111/cpf.12438. Epub 2017 Jul 14.


We aimed to develop an equation to predict peak VO2 in obese subjects undergoing CPET. In addition, we evaluated and compared three published equations. We randomized 346 obese subjects undergoing CPET into a group for developing the equation (n = 272) and a group for cross-validation (n = 74), compared through the Bland and Altman method. Height, sex and age were responsible for 85·5% of total variability of the peak VO2. Additional 1% and 0·7% of the variability were, respectively, explained by physical inactivity and diabetes. The equation devised was as follows: peakVO2mlmin-1=-677·8+(2135·9×heightm)+(706·8×sexmales=1;females=0)-(15·5×ageyears)-(161·1×physicalinactivityyes=1;no=0)-(176·3×diabetesyes=1;no=0). The mean difference between the estimated and measured peak VO2 was 7 ml min-1 , with a 23·9% bias. Published equations overestimated the peak VO2 by 35·3%, 49·1% and 46·2% bias. The equation developed in this study performed better in predicting peak VO2 in obese adults improving ramp protocol design and CRF evaluations in obese subjects.

Keywords: obesity; oxygen consumption; physical exertion; physical fitness; stress test.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Age Factors
  • Body Height
  • Cardiorespiratory Fitness*
  • Exercise Test*
  • Exercise Tolerance*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Biological*
  • Obesity / diagnosis
  • Obesity / physiopathology*
  • Oxygen Consumption*
  • Predictive Value of Tests
  • Prospective Studies
  • Random Allocation
  • Reproducibility of Results
  • Retrospective Studies
  • Sex Factors
  • Time Factors