Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Journal of Physiology |
| Vol/bind | 541 |
| Udgave nummer | Pt 1 |
| Sider (fra-til) | 273-81 |
| Antal sider | 8 |
| ISSN | 0022-3751 |
| Status | Udgivet - 2002 |
Bibliografisk note
Keywords: Adult; Bicycling; Blood Glucose; Blotting, Northern; Diet; Exercise; Fatty Acids, Nonesterified; Glucose; Glucose Transporter Type 4; Glycogen; Hormones; Humans; Insulin; Leg; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; RNA, Messenger; Regional Blood FlowCitationsformater
- APA
- Standard
- Harvard
- Vancouver
- Author
- BIBTEX
- RIS
I: Journal of Physiology, Bind 541, Nr. Pt 1, 2002, s. 273-81.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
}
TY - JOUR
T1 - Muscle glycogen content and glucose uptake during exercise in humans: influence of prior exercise and dietary manipulation.
AU - Steensberg, Adam
AU - van Hall, Gerrit
AU - Keller, Charlotte
AU - Osada, Takuya
AU - Schjerling, Peter
AU - Pedersen, Bente Klarlund
AU - Saltin, Bengt
AU - Febbraio, Mark A
N1 - Keywords: Adult; Bicycling; Blood Glucose; Blotting, Northern; Diet; Exercise; Fatty Acids, Nonesterified; Glucose; Glucose Transporter Type 4; Glycogen; Hormones; Humans; Insulin; Leg; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; RNA, Messenger; Regional Blood Flow
PY - 2002
Y1 - 2002
N2 - There are many factors that can influence glucose uptake by contracting skeletal muscle during exercise and although one may be intramuscular glycogen content, this relationship is at present not fully elucidated. To test the hypothesis that muscle glycogen concentration influences glucose uptake during exercise, 13 healthy men were studied during two series of experiments. Seven men completed 4 h of two-legged knee extensor exercise 16 h after reducing of muscle glycogen by completing 60 min of single-legged cycling (Series 1). A further six men completed 3 h of two-legged knee extensor exercise on two occasions: one after 60 min of two-legged cycling (16 h prior to the experimental trial) followed by a high carbohydrate diet (HCHO) and the other after the same exercise followed by a low carbohydrate diet (LCHO) (Series 2). Muscle glycogen was decreased by 40 % when comparing the pre-exercised leg (EL) with the control leg (CL) prior to exercise in Series 1. In addition, muscle glycogen was decreased by the same magnitude when comparing LCHO with HCHO in Series 2. In Series 1, glucose uptake was 3-fold higher in the first 60 min of exercise, in the presence of unchanged pre-exercise GLUT4 protein in EL compared with CL, suggesting that the lower glycogen, and not the exercise the day before, might have provided the stimulus for increased glucose uptake. Despite the same magnitude of difference in pre-exercise glycogen concentration when comparing Series 1 with Series 2, neither direct-nor isotopic tracer-determined glucose uptake was higher in LCHO compared with HCHO in Series 2. However, arterial concentrations of insulin and glucose were lower, while free fatty acids and adrenaline were higher in LCHO compared with HCHO. These data suggest that pre-exercise glycogen content may influence glucose uptake during subsequent exercise. However, this is only the case when delivery of substrates and hormones remains constant. When delivery of substrates and hormones is altered, the potential effect of glycogen on glucose uptake is negated.
AB - There are many factors that can influence glucose uptake by contracting skeletal muscle during exercise and although one may be intramuscular glycogen content, this relationship is at present not fully elucidated. To test the hypothesis that muscle glycogen concentration influences glucose uptake during exercise, 13 healthy men were studied during two series of experiments. Seven men completed 4 h of two-legged knee extensor exercise 16 h after reducing of muscle glycogen by completing 60 min of single-legged cycling (Series 1). A further six men completed 3 h of two-legged knee extensor exercise on two occasions: one after 60 min of two-legged cycling (16 h prior to the experimental trial) followed by a high carbohydrate diet (HCHO) and the other after the same exercise followed by a low carbohydrate diet (LCHO) (Series 2). Muscle glycogen was decreased by 40 % when comparing the pre-exercised leg (EL) with the control leg (CL) prior to exercise in Series 1. In addition, muscle glycogen was decreased by the same magnitude when comparing LCHO with HCHO in Series 2. In Series 1, glucose uptake was 3-fold higher in the first 60 min of exercise, in the presence of unchanged pre-exercise GLUT4 protein in EL compared with CL, suggesting that the lower glycogen, and not the exercise the day before, might have provided the stimulus for increased glucose uptake. Despite the same magnitude of difference in pre-exercise glycogen concentration when comparing Series 1 with Series 2, neither direct-nor isotopic tracer-determined glucose uptake was higher in LCHO compared with HCHO in Series 2. However, arterial concentrations of insulin and glucose were lower, while free fatty acids and adrenaline were higher in LCHO compared with HCHO. These data suggest that pre-exercise glycogen content may influence glucose uptake during subsequent exercise. However, this is only the case when delivery of substrates and hormones remains constant. When delivery of substrates and hormones is altered, the potential effect of glycogen on glucose uptake is negated.
M3 - Journal article
C2 - 12015435
SN - 0022-3751
VL - 541
SP - 273
EP - 281
JO - Journal of Physiology
JF - Journal of Physiology
IS - Pt 1
ER -