Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels

<p dir="ltr">This study investigated the mechanical efficiency (ME) and associated factors in obese, overweight, and normal-weight adolescent boys during incremental cycle exercise test to exhaustion. Forty-five sedentary adolescent boys (13–14 years old) were separated in three grou...

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Main Author: Georges Jabbour (754884) (author)
Other Authors: Lina Majed (7485380) (author)
Published: 2019
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_version_ 1864513520697081856
author Georges Jabbour (754884)
author2 Lina Majed (7485380)
author2_role author
author_facet Georges Jabbour (754884)
Lina Majed (7485380)
author_role author
dc.creator.none.fl_str_mv Georges Jabbour (754884)
Lina Majed (7485380)
dc.date.none.fl_str_mv 2019-03-15T03:00:00Z
dc.identifier.none.fl_str_mv 10.3389/fphys.2019.00265
dc.relation.none.fl_str_mv https://figshare.com/articles/journal_contribution/Mechanical_Efficiency_at_Different_Exercise_Intensities_Among_Adolescent_Boys_With_Different_Body_Fat_Levels/25398328
dc.rights.none.fl_str_mv CC BY 4.0
info:eu-repo/semantics/openAccess
dc.subject.none.fl_str_mv Biomedical and clinical sciences
Medical physiology
mechanical efficiency
energy consumption
obese
body mass
catecholamine
incremental cycle test to exhaustion
adolescent boys
dc.title.none.fl_str_mv Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
dc.type.none.fl_str_mv Text
Journal contribution
info:eu-repo/semantics/publishedVersion
text
contribution to journal
description <p dir="ltr">This study investigated the mechanical efficiency (ME) and associated factors in obese, overweight, and normal-weight adolescent boys during incremental cycle exercise test to exhaustion. Forty-five sedentary adolescent boys (13–14 years old) were separated in three groups according to the percentage of fat mass as follows: 15 normal-weight (NW) (body fat: 16.0 ± 1.9%), 15 overweight (OW) (body fat: 24.0 ± 1.6%), and 15 obese (OB) (body fat: 31.0 ± 3.0%). All groups completed an incremental cycle exercise to exhaustion in which energy consumption (E, W), ME (%), lipid oxidation rate (LO, %), plasma epinephrine and norepinephrine concentrations were determined consecutively at rest and at three intensity levels corresponding to 50 and 75% of each participant’s maximal heart rate (50%HRmax and 75%HRmax) and peak oxygen consumption (V˙O<sub>2peak</sub>). During the incremental cycle exercise test, plasma epinephrine, and norepinephrine responses as well as ME determined at 50%HRmax, 75%HRmax, and at VO<sub>2peak</sub> stages were significantly lower in OB compared to NW and OW individuals (ps < 0.01). Multiple linear regressions showed that body weight (ß = -0.64, p < 0.001), energy consumption (ß = -0.24, p < 0.05) and lipid oxidation (ß = 0.69, p < 0.01) were significant predictors of ME at 50%HRmax. However, at 75%HRmax and V˙O<sub>2peak</sub>, significant predictors of ME were epinephrine (ß = 0.34, ß = 0.49, respectively, ps = 0.01), norepinephrine (ß = 0.26, ß = 0.60, respectively, ps < 0.05) and power output (ß = 0.62, ß = 0.71, respectively, ps < 0.01). These findings suggest that excess in body weight exerts a negative effect on ME at a low intensity by increasing energy consumption for obese and overweight adolescent boys, while at higher intensities (75%HRmax and VO<sub>2peak</sub>) the lower ME could be better explained by the lower power output and catecholamine responses that were attenuated among obese and overweight adolescent boys.</p><h2>Other Information</h2><p dir="ltr">Published in: Frontiers in Physiology<br>License: <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank">https://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.3389/fphys.2019.00265" target="_blank">https://dx.doi.org/10.3389/fphys.2019.00265</a></p>
eu_rights_str_mv openAccess
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identifier_str_mv 10.3389/fphys.2019.00265
network_acronym_str Manara2
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oai_identifier_str oai:figshare.com:article/25398328
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spelling Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat LevelsGeorges Jabbour (754884)Lina Majed (7485380)Biomedical and clinical sciencesMedical physiologymechanical efficiencyenergy consumptionobesebody masscatecholamineincremental cycle test to exhaustionadolescent boys<p dir="ltr">This study investigated the mechanical efficiency (ME) and associated factors in obese, overweight, and normal-weight adolescent boys during incremental cycle exercise test to exhaustion. Forty-five sedentary adolescent boys (13–14 years old) were separated in three groups according to the percentage of fat mass as follows: 15 normal-weight (NW) (body fat: 16.0 ± 1.9%), 15 overweight (OW) (body fat: 24.0 ± 1.6%), and 15 obese (OB) (body fat: 31.0 ± 3.0%). All groups completed an incremental cycle exercise to exhaustion in which energy consumption (E, W), ME (%), lipid oxidation rate (LO, %), plasma epinephrine and norepinephrine concentrations were determined consecutively at rest and at three intensity levels corresponding to 50 and 75% of each participant’s maximal heart rate (50%HRmax and 75%HRmax) and peak oxygen consumption (V˙O<sub>2peak</sub>). During the incremental cycle exercise test, plasma epinephrine, and norepinephrine responses as well as ME determined at 50%HRmax, 75%HRmax, and at VO<sub>2peak</sub> stages were significantly lower in OB compared to NW and OW individuals (ps < 0.01). Multiple linear regressions showed that body weight (ß = -0.64, p < 0.001), energy consumption (ß = -0.24, p < 0.05) and lipid oxidation (ß = 0.69, p < 0.01) were significant predictors of ME at 50%HRmax. However, at 75%HRmax and V˙O<sub>2peak</sub>, significant predictors of ME were epinephrine (ß = 0.34, ß = 0.49, respectively, ps = 0.01), norepinephrine (ß = 0.26, ß = 0.60, respectively, ps < 0.05) and power output (ß = 0.62, ß = 0.71, respectively, ps < 0.01). These findings suggest that excess in body weight exerts a negative effect on ME at a low intensity by increasing energy consumption for obese and overweight adolescent boys, while at higher intensities (75%HRmax and VO<sub>2peak</sub>) the lower ME could be better explained by the lower power output and catecholamine responses that were attenuated among obese and overweight adolescent boys.</p><h2>Other Information</h2><p dir="ltr">Published in: Frontiers in Physiology<br>License: <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank">https://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.3389/fphys.2019.00265" target="_blank">https://dx.doi.org/10.3389/fphys.2019.00265</a></p>2019-03-15T03:00:00ZTextJournal contributioninfo:eu-repo/semantics/publishedVersiontextcontribution to journal10.3389/fphys.2019.00265https://figshare.com/articles/journal_contribution/Mechanical_Efficiency_at_Different_Exercise_Intensities_Among_Adolescent_Boys_With_Different_Body_Fat_Levels/25398328CC BY 4.0info:eu-repo/semantics/openAccessoai:figshare.com:article/253983282019-03-15T03:00:00Z
spellingShingle Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
Georges Jabbour (754884)
Biomedical and clinical sciences
Medical physiology
mechanical efficiency
energy consumption
obese
body mass
catecholamine
incremental cycle test to exhaustion
adolescent boys
status_str publishedVersion
title Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
title_full Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
title_fullStr Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
title_full_unstemmed Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
title_short Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
title_sort Mechanical Efficiency at Different Exercise Intensities Among Adolescent Boys With Different Body Fat Levels
topic Biomedical and clinical sciences
Medical physiology
mechanical efficiency
energy consumption
obese
body mass
catecholamine
incremental cycle test to exhaustion
adolescent boys