Mechanism of fatigue during maximal cycling exercise

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Publication Type thesis
School or College College of Health
Department Exercise & Sport Science
Author Tomas, Aleksandar
Title Mechanism of fatigue during maximal cycling exercise
Date 2007-07-23
Description Numerous research models have been designed to investigate potential mechanisms leading to fatigue during short-term maximal exercise. However, the neuromuscular mechanisms responsible for fatigue are still a matter of debate and interest, particularly in a human exercising model. Two likely mechanisms include excitation/relaxation and force-velocity kinetics. In this study short cycle cranks (120 mm) were used to accentuate fatigue associated with muscle excitation/relaxation and long cranks (220 mm) were used to emphasize contractile (force-velocity) origins of fatigue. Fatigue index (peak power - min power / peak power) was used to quantify fatigue. Ten competitive cyclists (7 male, 3 female) cycled maximally for 30 seconds on crank lengths of 120 mm at 136 rpm and 220 mm at 110 rpm using an isokinetic cycling protocol. Power data (averaged over a complete revolution of the cranks) were recorded at 10 Hz with a power meter. Peak power did not differ between cranks (901 ± 309 W for 120 mm, and 898 ± 3 1 1 W for 220 mm,/? = 0.873). Fatigue index differed significantly between cranks (57.5 ± 8.4% for 120 and 51.1 ± 11.3% for 220, p < 0.01). Work performed also differed significantly between cranks (18.0 ± 5.5 kJ for 120 and, 19.2 ± 5.9 kJ for 220 p < 0.01). These results suggest that fatigue during a maximal short-term exercise stems mainly from kinetics of excitation and relaxation of the sarcomere. Improving fatigue resistance during maximal exercise may require improvements in the processes of excitation and relaxation.
Type Text
Publisher University of Utah
Subject Bicycling; Kinetics
Dissertation Institution University of Utah
Dissertation Name MS
Language eng
Relation is Version of Digital reproduction of "Mechanism of fatigue during maximal cycling exercise" J. Willard Marriott Library Special Collections GV8.5 2007 .T64
Rights Management © Aleksandar Tomas
Format Medium application/pdf
Format Extent 51,927 bytes
Identifier us-etd2,119963
Source Original: University of Utah J. Willard Marriott Library Special Collections
Conversion Specifications Original scanned on Epson GT-30000 as 400 dpi to pdf using ABBYY FineReader 9.0 Professional Edition
ARK ark:/87278/s6tt55m8
Setname ir_etd
Date Created 2012-04-23
Date Modified 2012-05-17
ID 193934
Reference URL