Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Journal of Applied Physiology |
| Vol/bind | 106 |
| Udgave nummer | 5 |
| Sider (fra-til) | 1479-86 |
| Antal sider | 7 |
| ISSN | 8750-7587 |
| DOI | |
| Status | Udgivet - 2009 |
Bibliografisk note
Keywords: Acetylcarnitine; Adaptation, Physiological; Adenosine Triphosphatases; Adult; Biopsy; Citrate (si)-Synthase; Electron Transport Complex I; Electron Transport Complex IV; Energy Metabolism; Exercise; Exercise Test; Humans; Lactic Acid; Male; Oxygen Consumption; Polymerase Chain Reaction; Quadriceps Muscle; Young AdultAdgang til dokumentet
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I: Journal of Applied Physiology, Bind 106, Nr. 5, 2009, s. 1479-86.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
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TY - JOUR
T1 - Systematic analysis of adaptations in aerobic capacity and submaximal energy metabolism provides a unique insight into determinants of human aerobic performance
AU - Vollaard, Niels B J
AU - Constantin-Teodosiu, Dimitru
AU - Fredriksson, Katarina
AU - Rooyackers, Olav
AU - Jansson, Eva
AU - Greenhaff, Paul L
AU - Timmons, James A
AU - Sundberg, Carl Johan
N1 - Keywords: Acetylcarnitine; Adaptation, Physiological; Adenosine Triphosphatases; Adult; Biopsy; Citrate (si)-Synthase; Electron Transport Complex I; Electron Transport Complex IV; Energy Metabolism; Exercise; Exercise Test; Humans; Lactic Acid; Male; Oxygen Consumption; Polymerase Chain Reaction; Quadriceps Muscle; Young Adult
PY - 2009
Y1 - 2009
N2 - It has not been established which physiological processes contribute to endurance training-related changes (Delta) in aerobic performance. For example, the relationship between intramuscular metabolic responses at the intensity used during training and improved human functional capacity has not been examined in a longitudinal study. In the present study we hypothesized that improvements in aerobic capacity (Vo(2max)) and metabolic control would combine equally to explain enhanced aerobic performance. Twenty-four sedentary males (24 +/- 2 yr; 1.81 +/- 0.08 m; 76.6 +/- 11.3 kg) undertook supervised cycling training (45 min at 70% of pretraining Vo(2max)) 4 times/wk for 6 wk. Performance was determined using a 15-min cycling time trial, and muscle biopsies were taken before and after a 10-min cycle at 70% of pretraining Vo(2max) to quantify substrate metabolism. Substantial interindividual variability in training-induced adaptations was observed for most parameters, yet "low responders" for DeltaVo(2max) were not consistently low responders for other variables. While Vo(2max) and time trial performance were related at baseline (r(2) = 0.80, P < 0.001), the change in Vo(2max) was completely unrelated to the change in aerobic performance. The maximal parameters DeltaVe(max) and DeltaVeq(max) (DeltaVe/Vo(2max)) accounted for 64% of the variance in DeltaVo(2max) (P < 0.001), whereas Deltaperformance was related to changes in the submaximal parameters Veq(submax) (r(2) = 0.33; P < 0.01), muscle Deltalactate (r(2) = 0.32; P < 0.01), and Deltaacetyl-carnitine (r(2) = 0.29; P < 0.05). This study demonstrates that improvements in high-intensity aerobic performance in humans are not related to altered maximal oxygen transport capacity. Altered muscle metabolism may provide the link between training stimulus and improved performance, but metabolic parameters do not change in a manner that relates to aerobic capacity changes.
AB - It has not been established which physiological processes contribute to endurance training-related changes (Delta) in aerobic performance. For example, the relationship between intramuscular metabolic responses at the intensity used during training and improved human functional capacity has not been examined in a longitudinal study. In the present study we hypothesized that improvements in aerobic capacity (Vo(2max)) and metabolic control would combine equally to explain enhanced aerobic performance. Twenty-four sedentary males (24 +/- 2 yr; 1.81 +/- 0.08 m; 76.6 +/- 11.3 kg) undertook supervised cycling training (45 min at 70% of pretraining Vo(2max)) 4 times/wk for 6 wk. Performance was determined using a 15-min cycling time trial, and muscle biopsies were taken before and after a 10-min cycle at 70% of pretraining Vo(2max) to quantify substrate metabolism. Substantial interindividual variability in training-induced adaptations was observed for most parameters, yet "low responders" for DeltaVo(2max) were not consistently low responders for other variables. While Vo(2max) and time trial performance were related at baseline (r(2) = 0.80, P < 0.001), the change in Vo(2max) was completely unrelated to the change in aerobic performance. The maximal parameters DeltaVe(max) and DeltaVeq(max) (DeltaVe/Vo(2max)) accounted for 64% of the variance in DeltaVo(2max) (P < 0.001), whereas Deltaperformance was related to changes in the submaximal parameters Veq(submax) (r(2) = 0.33; P < 0.01), muscle Deltalactate (r(2) = 0.32; P < 0.01), and Deltaacetyl-carnitine (r(2) = 0.29; P < 0.05). This study demonstrates that improvements in high-intensity aerobic performance in humans are not related to altered maximal oxygen transport capacity. Altered muscle metabolism may provide the link between training stimulus and improved performance, but metabolic parameters do not change in a manner that relates to aerobic capacity changes.
U2 - 10.1152/japplphysiol.91453.2008
DO - 10.1152/japplphysiol.91453.2008
M3 - Journal article
C2 - 19196912
SN - 8750-7587
VL - 106
SP - 1479
EP - 1486
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 5
ER -