Oxygen uptake slow component: Enigma of the ‘excess’ oxygen used during heavy and severe exercise
Year: 2024
Type: article
Abstract: control of oxygen uptake, cycling biomechanics, heavy and severe exercise, muscle energetics, muscle fatigue, slow component In the 1980s, foundational physiology and exercise physiology texts considered that oxygen uptake ( VO 2 ) increased as a linear function of work rate (WR) on the cycle ergometer.Whereas this was true up to the maximum VO 2 ( VO 2 max ) for incremental exercise where WR was increased by 25 W or so per minute, for constant WR heavy-(i.e., >lactate threshold, LT) or severe-(>critical power, CP) intensity exercise there was an 'excess' VO 2 that manifested after the fast kinetics associated with the WR transition (Gaesser & Poole, 1996).This excess VO 2 became evident only after 2-3 min and for heavy exercise stabilized within 10 or so minutes or, for severe exercise, projected VO 2 to VO 2 max auguring exhaustion shortly thereafter.In the extreme, this VO 2 slow component ( VO 2 SC ) can amount to 1-1.5 L O 2 /min, eroding muscle efficiency.For physiologists seeking to better understand muscle energetics and exercise limitations, non-linear behaviour often provides powerful insights into systems control.However, at the time, explanations for the VO 2 SC were less than satisfying.Typically, researchers in the field had extrapolated the estimated O 2 cost of an array of physiological processes to calculate their putative role in the VO 2 SC during heavy/severe intensity exercise (Gaesser & Poole, 1996).Alternatively, the temporal correlation of these processes with the VO 2 SC was assessed to try and establish cause and effect.Principal processes considered included increasing ventilation, body
Source: Experimental Physiology
DOI: 10.1113/ep092326
Authors: David C. Poole, Glenn A. Gaesser
Institutions: Kansas State University, Arizona State University
Language: English
Subfield: Complementary and alternative medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,800
OpenAlex ID: W4403826044