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Power-duration relationship: physiology, fatigue and the limits of human performance

Burnley, Mark, Jones, Andrew M. (2016) Power-duration relationship: physiology, fatigue and the limits of human performance. European Journal of Sport Science, 18 (1). pp. 1-12. ISSN 1746-1391. E-ISSN 1536-7290. (doi:10.1080/17461391.2016.1249524) (KAR id:58396)


The duration that exercise can be maintained decreases as the power requirements increase. In this review we describe the power-duration (PD) relationship across the full range of attainable power outputs in humans. We show that a remarkably small range of power outputs are sustainable (power outputs below the critical power, CP). We also show that the origin of neuromuscular fatigue differs considerably depending on the exercise intensity domain in which exercise is performed. In the moderate domain (below the lactate threshold, LT), fatigue develops slowly and is predominantly of central origin (residing in the central nervous system). In the heavy domain (above LT but below CP), both central and peripheral (muscle) fatigue are observed. In this domain, fatigue is frequently correlated with the depletion of muscle glycogen. Severe-intensity exercise (above the CP) is associated with progressive derangements of muscle metabolic homeostasis and consequent peripheral fatigue. To counter these effects, muscle activity increases progressively, as does pulmonary oxygen uptake (VO2), with task failure being associated with the attainment of VO2max. Although the loss of homeostasis and thus fatigue develop more rapidly the higher the power output is above CP, the metabolic disturbance and the degree of peripheral fatigue reach similar values at task failure. We provide evidence that the failure to continue severe-intensity exercise is a physiological phenomenon involving multiple interacting mechanisms which indicate a mismatch between neuromuscular power demand and instantaneous power supply. Valid integrative models of fatigue must account for the PD relationship and its physiological basis.

Item Type: Article
DOI/Identification number: 10.1080/17461391.2016.1249524
Uncontrolled keywords: Endurance; fatigue; physiology; performance
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Sport and Exercise Sciences
Depositing User: Mark Burnley
Date Deposited: 04 Nov 2016 11:53 UTC
Last Modified: 16 Feb 2021 13:38 UTC
Resource URI: (The current URI for this page, for reference purposes)

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