Low-intensity training increases peak arm VO2 by enhancing both convective and diffusive O2 delivery.
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| Title: | Low-intensity training increases peak arm VO |
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| Authors: | Boushel, R., Ara, I., Gnaiger, E., Helge, J. W., González‐Alonso, J., Munck‐Andersen, T., Sondergaard, H., Damsgaard, R., Hall, G., Saltin, B., Calbet, J. A. L. |
| Source: | Acta Physiologica. May2014, Vol. 211 Issue 1, p122-134. 13p. 4 Charts, 4 Graphs. |
| Subjects: | Physiological transport of oxygen, Oxygen consumption, Muscle metabolism, Biopsy, Blood flow, Exercise |
| Abstract: | Aim It is an ongoing discussion the extent to which oxygen delivery and oxygen extraction contribute to an increased muscle oxygen uptake during dynamic exercise. It has been proposed that local muscle factors including the capillary bed and mitochondrial oxidative capacity play a large role in prolonged low-intensity training of a small muscle group when the cardiac output capacity is not directly limiting. The purpose of this study was to investigate the relative roles of circulatory and muscle metabolic mechanisms by which prolonged low-intensity exercise training alters regional muscle VO2. Methods In nine healthy volunteers (seven males, two females), haemodynamic and metabolic responses to incremental arm cycling were measured by the Fick method and biopsy of the deltoid and triceps muscles before and after 42 days of skiing for 6 h day−1 at 60% max heart rate. Results Peak pulmonary VO2 during arm crank was unchanged after training (2.38 ± 0.19 vs. 2.18 ± 0.2 L min−1 pre-training) yet arm VO2 (1.04 ± 0.08 vs. 0.83 ± 0.1 L min1, P < 0.05) and power output (137 ± 9 vs. 114 ± 10 Watts) were increased along with a higher arm blood flow (7.9 ± 0.5 vs. 6.8 ± 0.6 L min−1, P < 0.05) and expanded muscle capillary volume (76 ± 7 vs. 62 ± 4 mL, P < 0.05). Muscle O2 diffusion capacity (16.2 ± 1 vs. 12.5 ± 0.9 mL min−1 mHg−1, P < 0.05) and O2 extraction (68 ± 1 vs. 62 ± 1%, P < 0.05) were enhanced at a similar mean capillary transit time (569 ± 43 vs. 564 ± 31 ms) and P50 (35.8 ± 0.7 vs. 35 ± 0.8), whereas mitochondrial O2 flux capacity was unchanged (147 ± 6 mL kg min−1 vs. 146 ± 8 mL kg min−1). Conclusion The mechanisms underlying the increase in peak arm VO2 with prolonged low-intensity training in previously untrained subjects are an increased convective O2 delivery specifically to the muscles of the arm combined with a larger capillary-muscle surface area that enhance diffusional O2 conductance, with no apparent role of mitochondrial respiratory capacity. [ABSTRACT FROM AUTHOR] |
| Copyright of Acta Physiologica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Psychology and Behavioral Sciences Collection |
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| Header | DbId: pbh DbLabel: Psychology and Behavioral Sciences Collection An: 95661977 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Low-intensity training increases peak arm VO<subscript>2</subscript> by enhancing both convective and diffusive O<subscript>2</subscript> delivery. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Boushel%2C+R%2E%22">Boushel, R.</searchLink><br /><searchLink fieldCode="AR" term="%22Ara%2C+I%2E%22">Ara, I.</searchLink><br /><searchLink fieldCode="AR" term="%22Gnaiger%2C+E%2E%22">Gnaiger, E.</searchLink><br /><searchLink fieldCode="AR" term="%22Helge%2C+J%2E+W%2E%22">Helge, J. W.</searchLink><br /><searchLink fieldCode="AR" term="%22González‐Alonso%2C+J%2E%22">González‐Alonso, J.</searchLink><br /><searchLink fieldCode="AR" term="%22Munck‐Andersen%2C+T%2E%22">Munck‐Andersen, T.</searchLink><br /><searchLink fieldCode="AR" term="%22Sondergaard%2C+H%2E%22">Sondergaard, H.</searchLink><br /><searchLink fieldCode="AR" term="%22Damsgaard%2C+R%2E%22">Damsgaard, R.</searchLink><br /><searchLink fieldCode="AR" term="%22Hall%2C+G%2E%22">Hall, G.</searchLink><br /><searchLink fieldCode="AR" term="%22Saltin%2C+B%2E%22">Saltin, B.</searchLink><br /><searchLink fieldCode="AR" term="%22Calbet%2C+J%2E+A%2E+L%2E%22">Calbet, J. A. L.</searchLink> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Acta+Physiologica%22">Acta Physiologica</searchLink>. May2014, Vol. 211 Issue 1, p122-134. 13p. 4 Charts, 4 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Physiological+transport+of+oxygen%22">Physiological transport of oxygen</searchLink><br /><searchLink fieldCode="DE" term="%22Oxygen+consumption%22">Oxygen consumption</searchLink><br /><searchLink fieldCode="DE" term="%22Muscle+metabolism%22">Muscle metabolism</searchLink><br /><searchLink fieldCode="DE" term="%22Biopsy%22">Biopsy</searchLink><br /><searchLink fieldCode="DE" term="%22Blood+flow%22">Blood flow</searchLink><br /><searchLink fieldCode="DE" term="%22Exercise%22">Exercise</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Aim It is an ongoing discussion the extent to which oxygen delivery and oxygen extraction contribute to an increased muscle oxygen uptake during dynamic exercise. It has been proposed that local muscle factors including the capillary bed and mitochondrial oxidative capacity play a large role in prolonged low-intensity training of a small muscle group when the cardiac output capacity is not directly limiting. The purpose of this study was to investigate the relative roles of circulatory and muscle metabolic mechanisms by which prolonged low-intensity exercise training alters regional muscle VO2. Methods In nine healthy volunteers (seven males, two females), haemodynamic and metabolic responses to incremental arm cycling were measured by the Fick method and biopsy of the deltoid and triceps muscles before and after 42 days of skiing for 6 h day−1 at 60% max heart rate. Results Peak pulmonary VO2 during arm crank was unchanged after training (2.38 ± 0.19 vs. 2.18 ± 0.2 L min−1 pre-training) yet arm VO2 (1.04 ± 0.08 vs. 0.83 ± 0.1 L min1, P < 0.05) and power output (137 ± 9 vs. 114 ± 10 Watts) were increased along with a higher arm blood flow (7.9 ± 0.5 vs. 6.8 ± 0.6 L min−1, P < 0.05) and expanded muscle capillary volume (76 ± 7 vs. 62 ± 4 mL, P < 0.05). Muscle O2 diffusion capacity (16.2 ± 1 vs. 12.5 ± 0.9 mL min−1 mHg−1, P < 0.05) and O2 extraction (68 ± 1 vs. 62 ± 1%, P < 0.05) were enhanced at a similar mean capillary transit time (569 ± 43 vs. 564 ± 31 ms) and P50 (35.8 ± 0.7 vs. 35 ± 0.8), whereas mitochondrial O2 flux capacity was unchanged (147 ± 6 mL kg min−1 vs. 146 ± 8 mL kg min−1). Conclusion The mechanisms underlying the increase in peak arm VO2 with prolonged low-intensity training in previously untrained subjects are an increased convective O2 delivery specifically to the muscles of the arm combined with a larger capillary-muscle surface area that enhance diffusional O2 conductance, with no apparent role of mitochondrial respiratory capacity. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Acta Physiologica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1111/apha.12258 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 13 StartPage: 122 Subjects: – SubjectFull: Physiological transport of oxygen Type: general – SubjectFull: Oxygen consumption Type: general – SubjectFull: Muscle metabolism Type: general – SubjectFull: Biopsy Type: general – SubjectFull: Blood flow Type: general – SubjectFull: Exercise Type: general Titles: – TitleFull: Low-intensity training increases peak arm VO2 by enhancing both convective and diffusive O2 delivery. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Boushel, R. – PersonEntity: Name: NameFull: Ara, I. – PersonEntity: Name: NameFull: Gnaiger, E. – PersonEntity: Name: NameFull: Helge, J. W. – PersonEntity: Name: NameFull: González‐Alonso, J. – PersonEntity: Name: NameFull: Munck‐Andersen, T. – PersonEntity: Name: NameFull: Sondergaard, H. – PersonEntity: Name: NameFull: Damsgaard, R. – PersonEntity: Name: NameFull: Hall, G. – PersonEntity: Name: NameFull: Saltin, B. – PersonEntity: Name: NameFull: Calbet, J. A. L. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 05 Text: May2014 Type: published Y: 2014 Identifiers: – Type: issn-print Value: 17481708 Numbering: – Type: volume Value: 211 – Type: issue Value: 1 Titles: – TitleFull: Acta Physiologica Type: main |
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