Convective oxygen transport and fatigue.
نویسندگان
چکیده
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.
منابع مشابه
Fatigue Mechanisms Determining Exercise Performance Convective oxygen transport and fatigue
متن کامل
Invited Review HIGHLIGHTED TOPIC Fatigue Mechanisms Determining Exercise Performance Convective oxygen transport and fatigue
Amann M, Calbet JA. Convective oxygen transport and fatigue. J Appl Physiol 104: 861–870, 2008. First published October 25, 2007; doi:10.1152/japplphysiol.01008.2007.— During exercise, fatigue is defined as a reversible reduction in forceor powergenerating capacity and can be elicited by “central” and/or “peripheral” mechanisms. During skeletal muscle contractions, both aspects of fatigue may d...
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ورودعنوان ژورنال:
- Journal of applied physiology
دوره 104 3 شماره
صفحات -
تاریخ انتشار 2008