Glucose uptake is increased in trained vs. untrained muscle during heavy exercise
Deutscher übersetzter Titel: | Die Glukoseaufnahme bei maximaler Muskelarbeit ist im ausdauertrainierten Muskel gegenueber dem untrainierten erhoeht |
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Autor: | Kristiansen, S.; Gade, J.; Wojtaszewski, J.F.P.; Kiens, B.; Richter, E.A. |
Erschienen in: | Journal of applied physiology |
Veröffentlicht: | 89 (2000), 3, S. 1151-1158, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 8750-7587, 0021-8987, 0161-7567, 1522-1601 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU199912408429 |
Quelle: | BISp |
Abstract des Autors
Endurance training increases muscle content of glucose transporter proteins (GLUT-4) but decreases glucose utilization during exercise at a given absolute submaximal intensity. We hypothesized that glucose uptake might be higher in trained vs. untrained muscle during heavy exercise in the glycogen-depleted state. Eight untrained subjects endurance trained one thigh for 3 wk using a knee-extensor ergometer. The subjects then performed two-legged glycogen-depleting exercise and consumed a carbohydrate-free meal thereafter to keep muscle glycogen concentration low. The next morning, subjects performed dynamic knee extensions with both thighs simultaneously at 60, 80, and until exhaustion at 100% of each thighs peak workload. Glucose uptake was similar in both thighs during exercise at 60% of thigh peak workload. At the end of 80 and at 100% of peak workload, glucose uptake was on average 33 and 22% higher, respectively, in trained compared with untrained muscle (P<0.05). Training increased the muscle content of GLUT-4 by 66% (P<0.05). At exhaustion, glucose extraction correlated significantly (r=0.61) with total muscle GLUT-4 protein. Thus, when working at a high load with low glycogen concentrations, muscle glucose uptake is significantly higher in trained than in untrained muscle. This may be due to the higher GLUT-4 protein concentration in trained muscle. Verf.-Referat