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Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans

Intrinsic factors related to muscle metabolism may explain the differences in mechanical efficiency (ME) during exercise. Therefore, this study aimed to investigate the relationship between muscle metabolism and ME. Totally 17 healthy recreationally active male participants were recruited and divide...

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Autores principales: Laaksonen, Marko S., Kyröläinen, Heikki, Kemppainen, Jukka, Knuuti, Juhani, Kalliokoski, Kari K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6110921/
https://www.ncbi.nlm.nih.gov/pubmed/30246804
http://dx.doi.org/10.3389/fphys.2018.01171
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author Laaksonen, Marko S.
Kyröläinen, Heikki
Kemppainen, Jukka
Knuuti, Juhani
Kalliokoski, Kari K.
author_facet Laaksonen, Marko S.
Kyröläinen, Heikki
Kemppainen, Jukka
Knuuti, Juhani
Kalliokoski, Kari K.
author_sort Laaksonen, Marko S.
collection PubMed
description Intrinsic factors related to muscle metabolism may explain the differences in mechanical efficiency (ME) during exercise. Therefore, this study aimed to investigate the relationship between muscle metabolism and ME. Totally 17 healthy recreationally active male participants were recruited and divided into efficient (EF; n = 8) and inefficient (IE; n = 9) groups, which were matched for age (mean ± SD 24 ± 2 vs. 23 ± 2 years), BMI (23 ± 1 vs. 23 ± 2 kg m(−2)), physical activity levels (3.4 ± 1.0 vs. 4.1 ± 1.0 sessions/week), and [Formula: see text] O(2)peak (53 ± 3 vs. 52 ± 3 mL kg(−1) min(−1)), respectively, but differed for ME at 45% of [Formula: see text] O(2)peak intensity during submaximal bicycle ergometer test (EF 20.5 ± 3.5 vs. IE 15.4 ± 0.8%, P < 0.001). Using positron emission tomography, muscle blood flow (BF) and uptakes of oxygen (m [Formula: see text] O(2)), fatty acids (FAU) and glucose (GU) were measured during dynamic submaximal knee-extension exercise. Workload-normalized BF (EF 35 ± 14 vs. IE 34 ± 11 mL 100 g(−1) min(−1), P = 0.896), m [Formula: see text] O(2) (EF 4.1 ± 1.2 vs. IE 3.9 ± 1.2 mL 100 g(−1) min(−1), P = 0.808), and GU (EF 3.1 ± 1.8 vs. IE 2.6 ± 2.3 μmol 100 g(−1) min(−1), P = 0.641) as well as the delivery of oxygen, glucose, and FAU, as well as respiratory quotient were not different between the groups. However, FAU was significantly higher in EF than IE (3.1 ± 1.7 vs. 1.7 ± 0.6 μmol 100 g(−1) min(−1), P = 0.047) and it also correlated with ME (r = 0.56, P = 0.024) in the entire study group. EF group also demonstrated higher use of plasma FAU than IE, but no differences in use of plasma glucose and intramuscular energy sources were observed between the groups. These findings suggest that the effective use of plasma FAU is an important determinant of ME during exercise.
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spelling pubmed-61109212018-09-05 Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans Laaksonen, Marko S. Kyröläinen, Heikki Kemppainen, Jukka Knuuti, Juhani Kalliokoski, Kari K. Front Physiol Physiology Intrinsic factors related to muscle metabolism may explain the differences in mechanical efficiency (ME) during exercise. Therefore, this study aimed to investigate the relationship between muscle metabolism and ME. Totally 17 healthy recreationally active male participants were recruited and divided into efficient (EF; n = 8) and inefficient (IE; n = 9) groups, which were matched for age (mean ± SD 24 ± 2 vs. 23 ± 2 years), BMI (23 ± 1 vs. 23 ± 2 kg m(−2)), physical activity levels (3.4 ± 1.0 vs. 4.1 ± 1.0 sessions/week), and [Formula: see text] O(2)peak (53 ± 3 vs. 52 ± 3 mL kg(−1) min(−1)), respectively, but differed for ME at 45% of [Formula: see text] O(2)peak intensity during submaximal bicycle ergometer test (EF 20.5 ± 3.5 vs. IE 15.4 ± 0.8%, P < 0.001). Using positron emission tomography, muscle blood flow (BF) and uptakes of oxygen (m [Formula: see text] O(2)), fatty acids (FAU) and glucose (GU) were measured during dynamic submaximal knee-extension exercise. Workload-normalized BF (EF 35 ± 14 vs. IE 34 ± 11 mL 100 g(−1) min(−1), P = 0.896), m [Formula: see text] O(2) (EF 4.1 ± 1.2 vs. IE 3.9 ± 1.2 mL 100 g(−1) min(−1), P = 0.808), and GU (EF 3.1 ± 1.8 vs. IE 2.6 ± 2.3 μmol 100 g(−1) min(−1), P = 0.641) as well as the delivery of oxygen, glucose, and FAU, as well as respiratory quotient were not different between the groups. However, FAU was significantly higher in EF than IE (3.1 ± 1.7 vs. 1.7 ± 0.6 μmol 100 g(−1) min(−1), P = 0.047) and it also correlated with ME (r = 0.56, P = 0.024) in the entire study group. EF group also demonstrated higher use of plasma FAU than IE, but no differences in use of plasma glucose and intramuscular energy sources were observed between the groups. These findings suggest that the effective use of plasma FAU is an important determinant of ME during exercise. Frontiers Media S.A. 2018-08-21 /pmc/articles/PMC6110921/ /pubmed/30246804 http://dx.doi.org/10.3389/fphys.2018.01171 Text en Copyright © 2018 Laaksonen, Kyröläinen, Kemppainen, Knuuti and Kalliokoski. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Laaksonen, Marko S.
Kyröläinen, Heikki
Kemppainen, Jukka
Knuuti, Juhani
Kalliokoski, Kari K.
Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title_full Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title_fullStr Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title_full_unstemmed Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title_short Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans
title_sort muscle free fatty-acid uptake associates to mechanical efficiency during exercise in humans
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6110921/
https://www.ncbi.nlm.nih.gov/pubmed/30246804
http://dx.doi.org/10.3389/fphys.2018.01171
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