The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running
The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running
PURPOSE:
Exercise-induced muscle damage and lowered glycogen are common during heavy training periods, and may prolong recovery. We examined the effects of lowered glycogen on cardiorespiratory, metabolic and perceptual responses to downhill running.
METHODS:
Twelve men performed two downhill runs (-12 % gradient, 12.1 ± 1.1 km h(-1)) separated by 6 weeks, under normal (NORM) and reduced glycogen (RED) conditions in a crossover design. For RED, participants performed exhaustive cycling at 60 % [Formula: see text]O2max power (95 ± 13 min) in the evening, and the next morning completed a downhill run comprising of five stages of 8 min running, with 2 min recovery (1 % gradient, 8 km h(-1)) between each stage. Expired gas, heart rate, rating of perceived exertion (RPE) and blood lactate (bLa) and glucose were measured for each stage.
RESULTS:
Blood glucose (P < 0.05) and respiratory exchange ratio (P < 0.01) were lower in RED, than NORM, throughout the downhill run. RED demonstrated higher bLa until stage Four (P < 0.05), and RPE for stages Two and Five (P < 0.05).Ventilatory equivalent of carbon dioxide output ([Formula: see text]/[Formula: see text]) was higher for stages One (P < 0.01), Two and Five (P < 0.05), and oxygen uptake ([Formula: see text] E/[Formula: see text]O2) was lower for stages Three and Four (P < 0.05) for RED.
CONCLUSIONS:
Downhill running with reduced glycogen, elevated fat oxidation and bLa response, and, in part, increased effort perception. The alterations in [Formula: see text] E/[Formula: see text]O2 and bLa may suggest that carbon dioxide removal was somewhat impaired.
Muscle damage, glycogen, exercise physiology, Respiration rate, Effort perception, eccentric exercise, metabolism
1125-1133
Gavin, James Peter
e0d9b404-3f63-4855-8e64-bf1692e6cc3f
Myers, Steve D.
f1f200f5-f5b1-4eab-8542-4d435b50ed33
Willems, Marc E.T.
403242a2-7f54-4f8a-887d-d501ae5db0eb
May 2015
Gavin, James Peter
e0d9b404-3f63-4855-8e64-bf1692e6cc3f
Myers, Steve D.
f1f200f5-f5b1-4eab-8542-4d435b50ed33
Willems, Marc E.T.
403242a2-7f54-4f8a-887d-d501ae5db0eb
Gavin, James Peter, Myers, Steve D. and Willems, Marc E.T.
(2015)
The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running.
European Journal of Applied Physiology, 115 (5), .
(doi:10.1007/s00421-014-3094-4).
Abstract
PURPOSE:
Exercise-induced muscle damage and lowered glycogen are common during heavy training periods, and may prolong recovery. We examined the effects of lowered glycogen on cardiorespiratory, metabolic and perceptual responses to downhill running.
METHODS:
Twelve men performed two downhill runs (-12 % gradient, 12.1 ± 1.1 km h(-1)) separated by 6 weeks, under normal (NORM) and reduced glycogen (RED) conditions in a crossover design. For RED, participants performed exhaustive cycling at 60 % [Formula: see text]O2max power (95 ± 13 min) in the evening, and the next morning completed a downhill run comprising of five stages of 8 min running, with 2 min recovery (1 % gradient, 8 km h(-1)) between each stage. Expired gas, heart rate, rating of perceived exertion (RPE) and blood lactate (bLa) and glucose were measured for each stage.
RESULTS:
Blood glucose (P < 0.05) and respiratory exchange ratio (P < 0.01) were lower in RED, than NORM, throughout the downhill run. RED demonstrated higher bLa until stage Four (P < 0.05), and RPE for stages Two and Five (P < 0.05).Ventilatory equivalent of carbon dioxide output ([Formula: see text]/[Formula: see text]) was higher for stages One (P < 0.01), Two and Five (P < 0.05), and oxygen uptake ([Formula: see text] E/[Formula: see text]O2) was lower for stages Three and Four (P < 0.05) for RED.
CONCLUSIONS:
Downhill running with reduced glycogen, elevated fat oxidation and bLa response, and, in part, increased effort perception. The alterations in [Formula: see text] E/[Formula: see text]O2 and bLa may suggest that carbon dioxide removal was somewhat impaired.
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More information
Accepted/In Press date: 22 December 2014
e-pub ahead of print date: 1 January 2015
Published date: May 2015
Keywords:
Muscle damage, glycogen, exercise physiology, Respiration rate, Effort perception, eccentric exercise, metabolism
Identifiers
Local EPrints ID: 428527
URI: http://eprints.soton.ac.uk/id/eprint/428527
ISSN: 1439-6319
PURE UUID: a3fbb0b1-a0aa-4163-bfcb-29e437e00825
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Date deposited: 01 Mar 2019 17:30
Last modified: 16 Mar 2024 04:40
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Contributors
Author:
Steve D. Myers
Author:
Marc E.T. Willems
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