Non-invasive haemodynamic assessments using Innocor™ during standard graded exercise tests

Abstract

Cardiac output (Q) and stroke volume (VS) represent primary determinants of cardiovascular performance and should therefore be determined for performance diagnostics purposes. Since it is unknown, whether measurements of Q and VS can be performed by means of Innocor™ during standard graded exercise tests (GXTs), and whether current GXT stages are sufficiently long for the measurements to take place, we determined Q and V S at an early and late point in time on submaximal 2 min GXT stages. 16 male cyclists (age 25.4 ± 2.9 years, body mass 71.2 ± 5.0 kg) performed three GXTs and we determined Q and VS after 46 and 103 s at 69, 77, and 85% peak power. We found that the rebreathings could easily be incorporated into the GXTs and that Q and VS remained unchanged between the two points in time on the same GXT stage (69% peak power, Q: 18.1 ± 2.1 vs. 18.2 ± 2.3 l min-1, VS: 126 ± 18 vs. 123 ± 21 ml; 77% peak power, Q: 20.7 ± 2.6 vs. 21.0 ± 2.3 l min-1, VS: 132 ± 18 vs. 131 ± 18 ml; 85% peak power, Q: 21.6 ± 2.4 vs. 21.8 ± 2.7 l min-1, VS: 131 ± 17 vs. 131 ± 22 ml). We conclude that Innocor™ may be a useful device for assessing Q and V S during GXTs, and that the adaptation of Q and VS to exercise-to-exercise transitions at moderate to high submaximal power outputs is fast enough for 1 and 2 min GXT stage durations. © 2009 Springer-Verlag.