Alessio Del Torto1,2,3, Øyvind Skattebo4, Jostein Hallén4, Carlo Capelli4. 1. Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy. deltorto.alessio@spes.uniud.it. 2. Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, 0806, Oslo, Norway. deltorto.alessio@spes.uniud.it. 3. Department of Medical Area (DAME), University of Udine, Udine, Italy. deltorto.alessio@spes.uniud.it. 4. Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, 0806, Oslo, Norway.
Abstract
PURPOSE: We measured cardiac output ([Formula: see text]) during sub-maximal and supra-maximal exercise with inert gas rebreathing ([Formula: see text]) and modified cardio-impedance ([Formula: see text]) and we evaluated the repeatability of the two methods. METHODS: [Formula: see text]O2 and [Formula: see text] were measured twice in parallel with the two methods at sub-maximal (50-250 W) and supra-maximal exercise in 7 young subjects (25 ± 1 years; 74.4 ± 5.2 kg; 1.84 ± 0.07 m). RESULTS: [Formula: see text] and [Formula: see text] increased by 3.4 L·min-1 and by 5.1 L·min-1 per 1 L·min-1 of increase in [Formula: see text], respectively. Mean [Formula: see text] (23.3 ± 2.5 L·min-1) was 9% lower than [Formula: see text] (25.8 ± 2.2 L·min-1) during supra-maximal exercise. Bland-Altman analysis showed that: (i) bias ([Formula: see text]-[Formula: see text]) was significantly different from zero (- 0.65 ± 2.61 L·min-1) and; (ii) the ratios [Formula: see text] ÷ [Formula: see text] were linearly related with [Formula: see text], indicating that [Formula: see text] tended to overestimate [Formula: see text] in comparison with [Formula: see text] for values ranging from 10.0 to 15.0 L·min-1 and to underestimate it for larger values. The coefficient of variation was similar for sub-maximal values (8.6% vs. 7.7%; 95% CL: ×/÷1.31), but lower for [Formula: see text] (7.6%; 95% CL: ×/÷ 2.05) than for [Formula: see text] (27.7%; 95% CL: ×/÷2.54) at supra-maximal intensity. CONCLUSIONS: [Formula: see text] seems to represent a valuable alternative to invasive methods for assessing [Formula: see text] during sub-maximal exercise. The [Formula: see text] underestimation with respect to [Formula: see text] during supra-maximal exercise suggests that [Formula: see text] might be less optimal for supra-maximal intensities.
PURPOSE: We measured cardiac output ([Formula: see text]) during sub-maximal and supra-maximal exercise with inert gas rebreathing ([Formula: see text]) and modified cardio-impedance ([Formula: see text]) and we evaluated the repeatability of the two methods. METHODS: [Formula: see text]O2 and [Formula: see text] were measured twice in parallel with the two methods at sub-maximal (50-250 W) and supra-maximal exercise in 7 young subjects (25 ± 1 years; 74.4 ± 5.2 kg; 1.84 ± 0.07 m). RESULTS: [Formula: see text] and [Formula: see text] increased by 3.4 L·min-1 and by 5.1 L·min-1 per 1 L·min-1 of increase in [Formula: see text], respectively. Mean [Formula: see text] (23.3 ± 2.5 L·min-1) was 9% lower than [Formula: see text] (25.8 ± 2.2 L·min-1) during supra-maximal exercise. Bland-Altman analysis showed that: (i) bias ([Formula: see text]-[Formula: see text]) was significantly different from zero (- 0.65 ± 2.61 L·min-1) and; (ii) the ratios [Formula: see text] ÷ [Formula: see text] were linearly related with [Formula: see text], indicating that [Formula: see text] tended to overestimate [Formula: see text] in comparison with [Formula: see text] for values ranging from 10.0 to 15.0 L·min-1 and to underestimate it for larger values. The coefficient of variation was similar for sub-maximal values (8.6% vs. 7.7%; 95% CL: ×/÷1.31), but lower for [Formula: see text] (7.6%; 95% CL: ×/÷ 2.05) than for [Formula: see text] (27.7%; 95% CL: ×/÷2.54) at supra-maximal intensity. CONCLUSIONS: [Formula: see text] seems to represent a valuable alternative to invasive methods for assessing [Formula: see text] during sub-maximal exercise. The [Formula: see text] underestimation with respect to [Formula: see text] during supra-maximal exercise suggests that [Formula: see text] might be less optimal for supra-maximal intensities.
Authors: R Richard; E Lonsdorfer-Wolf; A Charloux; S Doutreleau; M Buchheit; M Oswald-Mammosser; E Lampert; B Mettauer; B Geny; J Lonsdorfer Journal: Eur J Appl Physiol Date: 2001-08 Impact factor: 3.078
Authors: A Charloux; E Lonsdorfer-Wolf; R Richard; E Lampert; M Oswald-Mammosser; B Mettauer; B Geny; J Lonsdorfer Journal: Eur J Appl Physiol Date: 2000-07 Impact factor: 3.078
Authors: Stefan P Mortensen; Ellen A Dawson; Chie C Yoshiga; Mads K Dalsgaard; Rasmus Damsgaard; Niels H Secher; José González-Alonso Journal: J Physiol Date: 2005-04-28 Impact factor: 5.182