Abstract The mechanism for slow pulmonary O 2 uptake (V̇ o 2 ) kinetics in patients with chronic heart failure (CHF) is unclear but may be due to limitations in the intramuscular control of O 2 utilization or O 2 delivery. Recent evidence of a transient overshoot in microvascular deoxygenation supports the latter. Prior (or warm-up) exercise can increase O 2 delivery in healthy individuals. We therefore aimed to determine whether prior exercise could increase muscle oxygenation and speed V̇ o 2 kinetics during exercise in CHF. Fifteen men with CHF (New York Heart Association I–III) due to left ventricular systolic dysfunction performed two 6-min moderate-intensity exercise transitions ( bouts 1 and 2 , separated by 6 min of rest) from rest to 90% of lactate threshold on a cycle ergometer. V̇ o 2 was measured using a turbine and a mass spectrometer, and muscle tissue oxygenation index (TOI) was determined by near-infrared spectroscopy. Prior exercise increased resting TOI by 5.3 ± 2.4% ( P = 0.001), attenuated the deoxygenation overshoot (−3.9 ± 3.6 vs. −2.0 ± 1.4%, P = 0.011), and speeded the V̇ o 2 time constant (τV̇ o 2 ; 49 ± 19 vs. 41 ± 16 s, P = 0.003). Resting TOI was correlated to τV̇ o 2 before ( R 2 = 0.51, P = 0.014) and after ( R 2 = 0.36, P = 0.051) warm-up exercise. However, the mean response time of TOI was speeded between bouts in half of the patients (26 ± 8 vs. 20 ± 8 s) and slowed in the remainder (32 ± 11 vs. 44 ± 16 s), the latter group having worse New York Heart Association scores ( P = 0.042) and slower V̇ o 2 kinetics ( P = 0.001). These data indicate that prior moderate-intensity exercise improves muscle oxygenation and speeds V̇ o 2 kinetics in CHF. The most severely limited patients, however, appear to have an intramuscular pathology that limits V̇ o 2 kinetics during moderate exercise. muscle oxygenation near-infrared spectroscopy prior exercise Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print October 2011 , doi: 10.​1152/​japplphysiol.​00779.​2011 Journal of Applied Physiology February 2012 vol. 112 no. 3 378-387 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: japplphysiol.00779.2011v1 112/3/378 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Alert me when eletters are published Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Responses Submit a response No responses published Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Bowen, T. S. Articles by Rossiter, H. B. PubMed PubMed citation Articles by Bowen, T. S. Articles by Rossiter, H. B. Related Content Load related web page information Current Issue February 2012, 112 (3) Alert me to new issues of Journal of Applied Physiology About the Journal Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 8750-7587 Online ISSN: 1522-1601 var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); var pageTracker = _gat._getTracker("UA-2924550-1"); pageTracker._trackPageview();

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