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Influence of priming exercise on pulmonary O2 uptake kinetics during transitions to high-intensity exercise from an elevated baseline

DiMenna, Fred J., Wilkerson, Daryl P., Burnley, Mark, Jones, Andrew M. (2008) Influence of priming exercise on pulmonary O2 uptake kinetics during transitions to high-intensity exercise from an elevated baseline. Journal of Applied Physiology, 105 (2). pp. 538-546. ISSN 1522-1601. (doi:10.1152/japplphysiol.90357.2008) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1152/japplphysiol.90357.2008

Abstract

It has been suggested that the slower O2 uptake (V?o2) kinetics observed when exercise is initiated from an elevated baseline metabolic rate are linked to an impairment of muscle O2 delivery. We hypothesized that “priming” exercise would significantly reduce the phase II time constant (?) during subsequent severe-intensity cycle exercise initiated from an elevated baseline metabolic rate. Seven healthy men completed exercise transitions to 70% of the difference between gas exchange threshold (GET) and peak V?o2 from a moderate-intensity baseline (90% GET) on three occasions in each of the “unprimed” and “primed” conditions. Pulmonary gas exchange, heart rate, and the electromyogram of m. vastus lateralis were measured during all tests. The phase II V?o2 kinetics were slower when severe exercise was initiated from a baseline of moderate exercise compared with unloaded pedaling (mean ± SD ?, 42 ± 15 vs. 33 ± 8 s; P < 0.05), but were not accelerated by priming exercise (42 ± 17 s; P > 0.05). The amplitude of the V?o2 slow component and the change in electromyogram from minutes 2 to 6 were both significantly reduced following priming exercise (V?o2 slow component: from 0.47 ± 0.09 to 0.27 ± 0.13 l/min; change in integrated electromyogram between 2 and 6 min: from 51 ± 35 to 26±43% of baseline; P < 0.05 for both comparisons). These results indicate that the slower phase II V?o2 kinetics observed during transitions to severe exercise from an elevated baseline are not altered by priming exercise, but that the reduced V?o2 slow component may be linked to changes in muscle fiber activation.

Item Type: Article
DOI/Identification number: 10.1152/japplphysiol.90357.2008
Additional information: number of additional authors: 3;
Uncontrolled keywords: Oxygen uptake kinetics, phase II time constant, oxygen uptake slow component, work-to-work transition.
Subjects: H Social Sciences
Divisions: Faculties > Sciences > School of Sport and Exercise Sciences
Depositing User: Stewart Brownrigg
Date Deposited: 07 Mar 2014 00:05 UTC
Last Modified: 23 Jan 2020 04:08 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/40354 (The current URI for this page, for reference purposes)
Burnley, Mark: https://orcid.org/0000-0003-3407-561X
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