Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise
Hopker, James G., Caporaso, Giuseppe, Azzalin, Andrea, Carpenter, R. and Marcora, Samuele M. 2016. Locomotor Muscle Fatigue Does Not Alter Oxygen Uptake Kinetics during High-Intensity Exercise. Frontiers in Physiology. 7 (463).
|Authors||Hopker, James G., Caporaso, Giuseppe, Azzalin, Andrea, Carpenter, R. and Marcora, Samuele M.|
The V˙O2 slow component (V˙O2sc) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min−1. Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and V˙O2max determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue (P = 0.03), the V˙O2sc was not significantly different between the pre-fatigue (464 ± 301 mL·min−1) and the control (556 ± 223 mL·min−1) condition (P = 0.50). Blood lactate response was not significantly different between conditions (P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition (P < 0.01) suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the V˙O2 kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the V˙O2sc is strongly associated with locomotor muscle fatigue.
|Keywords||locomotor muscle fatigue; slow component; efficiency; power output; aerobic exercise; cycling|
|Journal||Frontiers in Physiology|
|Journal citation||7 (463)|
Carpenter R - 2016 Locomotor muscle fatigue does not alter O2 kinetics during high intensity exercise.pdf
|Digital Object Identifier (DOI)||doi:10.3389/fphys.2016.00463|
|13 Oct 2016|
|Publication process dates|
|Deposited||03 Nov 2016|
|Accepted||27 Sep 2016|
|Copyright information||© 2016 The Authors. This document is protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permission.|
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