Cardiorespiratory and metabolic responses after exercise-induced muscle damage: the influence of lowered glycogen
Cardiorespiratory and metabolic responses after exercise-induced muscle damage: the influence of lowered glycogen
BACKGROUND: We examined the effect of early-onset of muscle damage and low muscle glycogen on cardiorespiratory and metabolic responses to low-intensity exercise.
METHODS: Twelve men cycled for 10 min at 50% maximal oxygen uptake before, and 12 h after a morning downhill run (five, 8 min bouts at -12% gradient, with 2 min rests) under normal (NORM) and lowered glycogen (LOW) conditions, following a cross-over design with conditions separated by six weeks. Cardiorespiratory responses were recorded, with oxidation measures derived from stoichiometry equations.
RESULTS: Muscle damage symptoms post-downhill (0 h) were similar between conditions. Carbon dioxide ventilatory equivalent increased 12 h post-downhill for LOW (P<0.05), but not NORM (P=0.7). A trend towards decreased respiratory exchange ratio (RER) was shown 12 h post-downhill for LOW (1.00±0.07 to 0.89±0.12, P=0.06), but not NORM (0.94±0.11 to 0.94±0.08; P=0.6). Twelve hours after LOW downhill running fat oxidation increased (0.21±0.18 g·min-1 to 0.36±0.27 g·min-1; P<0.05) and carbohydrate oxidation decreased (2.68±0.52 g·min-1 to 1.98±0.75 g·min-1; P<0.05); NORM oxidation rates were unchanged (fat: 0.26±0.18 g·min-1 to 0.33±0.18 g·min-1; P=0.5; carbohydrate: 2.51±0.49 g·min-1 to 2.29±0.47 g·min-1; P=0.3).
CONCLUSIONS: Cycling at low-intensity 12 h post-downhill running with lowered muscle glycogen increased fat oxidation, decreased carbohydrate oxidation and elevated carbon dioxide ventilation. Damaging exercise with reduced glycogen availability increases fat utilization during subsequent low-intensity exercise as little as 12 h later.
Adult, Athletes, Athletic Injuries, Blood Glucose, Cardiorespiratory Fitness, Exercise, Fats, Glycogen, Humans, Male, Muscle, Skeletal, Oxygen Consumption, Running, Young Adult, Journal Article
332-340
Gavin, James P
e0d9b404-3f63-4855-8e64-bf1692e6cc3f
Myers, Stephen D
df70fcbd-572b-4579-98fc-3133c8b3de21
Willems, Mark E
0826558e-ea7f-4a40-9434-81ca95a7582c
March 2018
Gavin, James P
e0d9b404-3f63-4855-8e64-bf1692e6cc3f
Myers, Stephen D
df70fcbd-572b-4579-98fc-3133c8b3de21
Willems, Mark E
0826558e-ea7f-4a40-9434-81ca95a7582c
Gavin, James P, Myers, Stephen D and Willems, Mark E
(2018)
Cardiorespiratory and metabolic responses after exercise-induced muscle damage: the influence of lowered glycogen.
The Journal of sports medicine and physical fitness, 58 (3), .
(doi:10.23736/S0022-4707.16.06644-5).
Abstract
BACKGROUND: We examined the effect of early-onset of muscle damage and low muscle glycogen on cardiorespiratory and metabolic responses to low-intensity exercise.
METHODS: Twelve men cycled for 10 min at 50% maximal oxygen uptake before, and 12 h after a morning downhill run (five, 8 min bouts at -12% gradient, with 2 min rests) under normal (NORM) and lowered glycogen (LOW) conditions, following a cross-over design with conditions separated by six weeks. Cardiorespiratory responses were recorded, with oxidation measures derived from stoichiometry equations.
RESULTS: Muscle damage symptoms post-downhill (0 h) were similar between conditions. Carbon dioxide ventilatory equivalent increased 12 h post-downhill for LOW (P<0.05), but not NORM (P=0.7). A trend towards decreased respiratory exchange ratio (RER) was shown 12 h post-downhill for LOW (1.00±0.07 to 0.89±0.12, P=0.06), but not NORM (0.94±0.11 to 0.94±0.08; P=0.6). Twelve hours after LOW downhill running fat oxidation increased (0.21±0.18 g·min-1 to 0.36±0.27 g·min-1; P<0.05) and carbohydrate oxidation decreased (2.68±0.52 g·min-1 to 1.98±0.75 g·min-1; P<0.05); NORM oxidation rates were unchanged (fat: 0.26±0.18 g·min-1 to 0.33±0.18 g·min-1; P=0.5; carbohydrate: 2.51±0.49 g·min-1 to 2.29±0.47 g·min-1; P=0.3).
CONCLUSIONS: Cycling at low-intensity 12 h post-downhill running with lowered muscle glycogen increased fat oxidation, decreased carbohydrate oxidation and elevated carbon dioxide ventilation. Damaging exercise with reduced glycogen availability increases fat utilization during subsequent low-intensity exercise as little as 12 h later.
Text
Gavin et al. 2017_cardio after EIMD
- Accepted Manuscript
More information
Published date: March 2018
Keywords:
Adult, Athletes, Athletic Injuries, Blood Glucose, Cardiorespiratory Fitness, Exercise, Fats, Glycogen, Humans, Male, Muscle, Skeletal, Oxygen Consumption, Running, Young Adult, Journal Article
Identifiers
Local EPrints ID: 429114
URI: http://eprints.soton.ac.uk/id/eprint/429114
ISSN: 0022-4707
PURE UUID: 6cfe4e36-be90-4d8b-be9d-0ece29781c55
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Date deposited: 21 Mar 2019 17:30
Last modified: 16 Mar 2024 07:38
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Author:
Stephen D Myers
Author:
Mark E Willems
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