Format

Send to

Choose Destination
See comment in PubMed Commons below
J Appl Physiol (1985). 2008 Mar;104(3):861-70. Epub 2007 Oct 25.

Convective oxygen transport and fatigue.

Author information

1
The John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison Medical School, 4245 Medical Science Center, 1300 University Avenue, Madison, WI 53706. amann@wisc.edu

Abstract

During exercise, fatigue is defined as a reversible reduction in force- or power-generating capacity and can be elicited by "central" and/or "peripheral" mechanisms. During skeletal muscle contractions, both aspects of fatigue may develop independent of alterations in convective O(2) delivery; however, reductions in O(2) supply exacerbate and increases attenuate the rate of accumulation. In this regard, peripheral fatigue development is mediated via the O(2)-dependent rate of accumulation of metabolic by-products (e.g., inorganic phosphate) and their interference with excitation-contraction coupling within the myocyte. In contrast, the development of O(2)-dependent central fatigue is elicited 1) by interference with the development of central command and/or 2) via inhibitory feedback on central motor drive secondary to the peripheral effects of low convective O(2) transport. Changes in convective O(2) delivery in the healthy human can result from modifications in arterial O(2) content, blood flow, or a combination of both, and they can be induced via heavy exercise even at sea level; these changes are exacerbated during acute and chronic exposure to altitude. This review focuses on the effects of changes in convective O(2) delivery on the development of central and peripheral fatigue.

PMID:
17962570
DOI:
10.1152/japplphysiol.01008.2007
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center