Abstract
Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before the marathon and decreased to 148 +/- 39 mmol/kg dry weight immediately afterward. Despite a carbohydrate-rich diet (containing at least 7 g carbohydrate.kg body mass-1.day-1), the muscle glycogen concentration remained 30% lower than before-race values 2 days after the race, whereas it had returned to before-race levels 7 days after the race. We conclude that the total GLUT-4 protein content is unaltered in the lateral gastrocnemius after a competitive marathon and that the slow recovery of muscle glycogen after the race apparently involves factors other than changes in the total content of this protein.
| Original language | English |
|---|---|
| Journal | Journal of Applied Physiology |
| Volume | 83 |
| Issue number | 5 |
| Pages (from-to) | 1482-1485 |
| Number of pages | 4 |
| ISSN | 8750-7587 |
| Publication status | Published - 1997 |
Keywords
- Adult
- Creatine Kinase
- Diet
- Exercise
- Glucose Transporter Type 4
- Glycogen
- Glycogen Synthase
- Humans
- Male
- Monosaccharide Transport Proteins
- Muscle Proteins
- Muscle, Skeletal
- Physical Endurance
- Running
- Time Factors