Validity of reporting oxygen uptake efficiency slope from submaximal exercise using respiratory exchange ratio as secondary criterion.

Wilby Williamson,Ulf Ekelund,Soren Brage,Kate Westgate,Jonathan Fuld,Karl Sylvester

doi:10.1155/2012/874020

Abstract

Background. Oxygen uptake efficiency slope (OUES) is a reproducible, objective marker of cardiopulmonary function. OUES is reported as being relatively independent of exercise intensity. Practical guidance and criteria for reporting OUES from submaximal tests has not been established. Objective. Evaluate the use of respiratory exchange ratio (RER) as a secondary criterion for reporting OUES. Design. 100 healthy volunteers (53 women) completed a ramped treadmill protocol to exhaustive exercise. OUES was calculated from data truncated to RER levels from 0.85 to 1.2 and compared to values generated from full test data. Results. Mean (sd) OUES from full test data and data truncated to RER 1.0 and RER 0.9 was 2814 (718), 2895 (730), and 2810 (789) mL/min per 10-fold increase in VE, respectively. Full test OUES was highly correlated with OUES from RER 1.0 (r = 0.9) and moderately correlated with OUES from RER 0.9 (r = 0.79). Conclusion. OUES values peaked in association with an RER level of 1.0. Sub-maximal OUES values are not independent of exercise intensity. There is a significant increase in OUES value as exercise moves from low to moderate intensity. RER can be used as a secondary criterion to define this transition.

Highlights

Exercise testing allows quantification of cardiopulmonary function providing valuable diagnostic and prognostic data
Mean time to VAT was 821 seconds associated with an respiratory exchange ratio (RER) of 0.92
The current study has presented the characteristics of Oxygen uptake efficiency slope (OUES) in relation to RER values

Summary

Introduction

Exercise testing allows quantification of cardiopulmonary function providing valuable diagnostic and prognostic data. Peak and maximal cardiopulmonary exercise testing are gold standard modalities [1]. To maintain safety and efficiency, termination criteria are within the moderate, nonmaximal exercise intensity range. Tests stopped within 80–90% of maximal heart rate or when respiratory exchange ratio (RER). OUES is reported as being relatively independent of exercise intensity. Practical guidance and criteria for reporting OUES from submaximal tests has not been established. Evaluate the use of respiratory exchange ratio (RER) as a secondary criterion for reporting OUES. OUES was calculated from data truncated to RER levels from 0.85 to 1.2 and compared to values generated from full test data. OUES values peaked in association with an RER level of 1.0. Submaximal OUES values are not independent of exercise intensity. There is a significant increase in OUES value as exercise moves from low to moderate intensity. RER can be used as a secondary criterion to define this transition

Objectives

Results

Discussion

Conclusion