Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists

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Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists. / Christensen, Peter Møller; Gunnarsson, Thomas Gunnar Petursson; Thomassen, Martin; Wilkerson, Daryl P; Nielsen, Jens Jung; Bangsbo, Jens.

I: Physiological Reports, Bind 3, Nr. 7, e12428, 2015.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Christensen, PM, Gunnarsson, TGP, Thomassen, M, Wilkerson, DP, Nielsen, JJ & Bangsbo, J 2015, 'Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists', Physiological Reports, bind 3, nr. 7, e12428. https://doi.org/10.14814/phy2.12428

APA

Christensen, P. M., Gunnarsson, T. G. P., Thomassen, M., Wilkerson, D. P., Nielsen, J. J., & Bangsbo, J. (2015). Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists. Physiological Reports, 3(7), [e12428]. https://doi.org/10.14814/phy2.12428

Vancouver

Christensen PM, Gunnarsson TGP, Thomassen M, Wilkerson DP, Nielsen JJ, Bangsbo J. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists. Physiological Reports. 2015;3(7). e12428. https://doi.org/10.14814/phy2.12428

Author

Christensen, Peter Møller ; Gunnarsson, Thomas Gunnar Petursson ; Thomassen, Martin ; Wilkerson, Daryl P ; Nielsen, Jens Jung ; Bangsbo, Jens. / Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists. I: Physiological Reports. 2015 ; Bind 3, Nr. 7.

Bibtex

@article{856f6fc486c1412e9551d3d74c8eabf0,
title = "Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists",
abstract = "The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65{\%} V˙O2-max) and INT (286 ± 17 W ~85{\%} V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50{\%} reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics.",
author = "Christensen, {Peter M{\o}ller} and Gunnarsson, {Thomas Gunnar Petursson} and Martin Thomassen and Wilkerson, {Daryl P} and Nielsen, {Jens Jung} and Jens Bangsbo",
note = "CURIS 2015 NEXS 262",
year = "2015",
doi = "10.14814/phy2.12428",
language = "English",
volume = "3",
journal = "Physiological Reports",
issn = "2051-817X",
publisher = "Wiley Periodicals, Inc.",
number = "7",

}

RIS

TY - JOUR

T1 - Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists

AU - Christensen, Peter Møller

AU - Gunnarsson, Thomas Gunnar Petursson

AU - Thomassen, Martin

AU - Wilkerson, Daryl P

AU - Nielsen, Jens Jung

AU - Bangsbo, Jens

N1 - CURIS 2015 NEXS 262

PY - 2015

Y1 - 2015

N2 - The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics.

AB - The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics.

U2 - 10.14814/phy2.12428

DO - 10.14814/phy2.12428

M3 - Journal article

C2 - 26152692

VL - 3

JO - Physiological Reports

JF - Physiological Reports

SN - 2051-817X

IS - 7

M1 - e12428

ER -

ID: 142029320