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Published on: February 20, 2017
VO2@RER1.0: a novel submaximal cardiopulmonary exercise index
Clifford Chin1, Jeffrey Kazmucha, Nancy Kim
1Division of Pediatric Cardiology, Stanford University, Palo Alto, CA 94304, USA. clifford@leland.stanford.edu
Maximal oxygen consumption (VO2max) is effort-dependent. A new submaximal index, VO2 at respiratory exchange ratio 1.0 (VO2@RER1.0), accurately predicts functional capacity without subjectivity.
Area of Science:
- Cardiopulmonary exercise testing
- Pediatric exercise physiology
- Functional capacity assessment
Background:
- Maximal oxygen consumption (VO2max) is the gold standard for functional capacity but is effort-dependent.
- Objective assessment is needed for individuals unable to reach maximal exertion.
- Respiratory exchange ratio (RER) provides insight into exercise intensity.
Purpose of the Study:
- To evaluate VO2 at respiratory exchange ratio 1.0 (VO2@RER1.0) as a submaximal index of functional capacity.
- To determine the predictive value of VO2@RER1.0 for peak VO2.
- To establish normative data for VO2@RER1.0 in pediatric subjects.
Main Methods:
- Cycle ergometer cardiopulmonary exercise testing was performed on 305 pediatric subjects.
- Subjects exercised to exhaustion, achieving a peak RER ≥ 1.10.
- Linear regression and contingency table analyses were used to assess VO2@RER1.0 against predicted VO2max.
Main Results:
- VO2@RER1.0 was analyzed as a function of predicted VO2 in subjects reaching ≥80% of predicted VO2max.
- A normative regression line and equation were established.
- Abnormal VO2@RER1.0 demonstrated high predictive values (83-85%) and accuracy (84%) for abnormal peak VO2.
Conclusions:
- VO2@RER1.0 is a sensitive, specific, and predictive submaximal index of functional capacity.
- This objective index is easily identifiable and may assist in evaluating subjects with limited exercise tolerance.
- VO2@RER1.0 offers a reliable alternative to VO2max assessment in specific populations.
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