Reliability of Measurements with Innocor^TM during Exercise

Abstract

Cardiac output represents the primary determinant of cardiovascular function. Therefore, understanding how cardiac output is regulated during exercise is crucial. A recently developed tool for determining cardiac output is the Innocor™ rebreathing system, which also incorporates an ergospirometry unit. So far, Innocor™'s test-retest reliability under exercise conditions has not been determined in healthy participants. Therefore, 15 male and 15 female healthy participants [30.6 y (SD 4.5); 68.0 kg (SD 10.5)] performed 2 test sessions, each consisting of 2 graded exercise tests to volitional exhaustion. We determined intra- and inter-session reliability of cardiac output, oxygen consumption, carbon dioxide output, and ventilation at 130 W and at peak exercise. For cardiac output, we found averaged coefficients of variation ranging from 4.3 (intra-session, 130 W) to 10.0% (inter-session, rest). For oxygen consumption, coefficients of variation ranged from 3.4 (intra-session, peak) to 5.7% (inter-session, peak). Coefficients of variation for carbon dioxide output were between 4.4 (intra-session, peak) and 6.6% (inter-session, peak), and for ventilation between 5.1 (intra-session, 130 W) and 7.0% (intra-session, peak). Innocor™ delivers safe and reliable measurements of cardiac output, gas exchange, and ventilation. Therefore, Innocor™ can be used to assess these parameters in exercise physiology studies as well as in performance diagnostics.

Key words

reproducibility - inert gas rebreathing - cardiac output - ergospirometry - oxygen consumption - performance diagnostics

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