Table 2.
Skeletal muscle metabolites at rest and following 30 min of exercise at 50 and 80%
before (0) and 12 and 24 weeks after twice daily oral ingestion of either 80 g of carbohydrate (Control; n= 7) or 80 g of carbohydrate containing 2 g l-carnitine tartrate (Carnitine; n= 7)
| Rest | 50%
|
80%
|
|||||
|---|---|---|---|---|---|---|---|
| Control | Carnitine | Control | Carnitine | Control | Carnitine | ||
| 0 | PCr | 79.3 ± 8.6 | 90.0 ± 5.2 | 71.0 ± 8.0 | 64.8 ± 12.2 | 41.9 ± 5.2 | 38.1 ± 5.3 |
| PCr/ATP ratio | 3.5 ± 0.4 | 3.6 ± 0.2 | 3.1 ± 0.1 | 2.9 ± 0.3 | 1.6 ± 0.2 | 1.4 ± 0.2 | |
| Glycogen | 430.2 ± 29.2 | 436.3 ± 20.5 | 380.7 ± 28.4 | 386.4 ± 10.1 | 235.2 ± 29.8 | 260.5 ± 22.7 | |
| Lactate | 3.7 ± 1.4 | 3.0 ± 0.8 | 7.1 ± 2.4 | 7.5 ± 2.5 | 29.0 ± 4.7 | 27.5 ± 5.5 | |
| Acetylcarnitine | 2.6 ± 0.4 | 2.5 ± 0.6 | 6.7 ± 0.8 | 8.1 ± 1.6 | 15.8 ± 0.8 | 17.4 ± 0.9 | |
| Free carnitine | 17.9 ± 1.8 | 18.0 ± 1.8 | 14.0 ± 1.4 | 14.5 ± 1.5 | 9.4 ± 1.3 | 5.1 ± 0.9 | |
| Acyl-carnitine | 0.9 ± 0.1 | 0.9 ± 0.1 | 0.8 ± 0.1 | 1.0 ± 0.1 | 1.3 ± 0.1 | 1.0 ± 0.1 | |
| 12 | PCr | 87.8 ± 4.5 | 88.7 ± 5.8 | 63.6 ± 10.6 | 69.5 ± 6.3 | 47.9 ± 5.9 | 51.9 ± 8.6 |
| PCr/ATP ratio | 3.6 ± 0.2 | 4.1 ± 0.5 | 3.1 ± 0.3 | 2.8 ± 0.2 | 1.8 ± 0.3 | 2.0 ± 0.3 | |
| Glycogen | 441.9 ± 34.0 | 393.2 ± 10.0 | 384.5 ± 40.4 | 346.4 ± 15.8 | 206.0 26.8 | 181.6 ± 17.6 | |
| Lactate | 4.5 ± 0.6 | 3.2 ± 0.5 | 7.9 ± 2.3 | 5.5 ± 0.9 | 37.9 ± 5.0 | 32.0 ± 5.8 | |
| Acetylcarnitine | 3.2 ± 0.6 | 4.4 ± 1.1 | 7.8 ± 1.7 | 7.0 ± 1.1 | 12.6 ± 1.3 | 15.6 ± 2.0 | |
| Free carnitine | 16.2 ± 1.9 | 19.5 ± 2.0 | 12.7 ± 1.5 | 15.8 ± 1.3 | 7.9 ± 1.0 | 6.5 ± 1.0 | |
| Acyl-carnitine | 0.7 ± 0.1 | 0.9 ± 0.2 | 0.9 ± 0.1 | 0.8 ± 0.1 | 0.8 ± 0.1 | 1.6 ± 0.4 | |
| 24 | PCr | 70.3 ± 9.6 | 83.5 ± 9.0 | 70.3 ± 5.0 | 68.4 ± 13.0 | 33.3 ± 6.5 | 48.6 ± 6.3 |
| PCr/ATP ratio | 3.7 ± 0.1 | 3.4 ± 0.3 | 2.5 ± 0.4 | 3.0 ± 0.3 | 1.3 ± 0.2 | 2.7 ± 0.3*† | |
| Glycogen | 386.4 ± 33.8 | 467.6 ± 24.8 | 326.1 ± 33.9 | 440.7 ± 24.1* | 146.8 ± 17.4 | 251.7 ± 37.7* | |
| Lactate | 4.4 ± 0.8 | 4.5 ± 1.0 | 7.7 ± 1.2 | 5.5 ± 0.6 | 44.4 ± 6.9 | 25.0 ± 4.1* | |
| Acetylcarnitine | 2.8 ± 0.7 | 2.7 ± 0.8 | 7.7 ± 1.7 | 6.7 ± 1.5 | 15.8 ± 1.4 | 18.4 ± 1.7 | |
| Free carnitine | 15.9 ± 1.6 | 20.7 ± 2.2 | 11.0 ± 1.3 | 19.6 ± 2.4**† | 5.4 ± 0.7 | 8.8 ± 1.7 | |
| Acyl-carnitine | 0.9 ± 0.2 | 0.8 ± 0.1 | 0.7 ± 0.1 | 1.0 ± 0.2 | 0.9 ± 0.1 | 1.2 ± 0.4 | |
All values are means ±s.e.m. and expressed as mmol (kg dry muscle)−1. Significantly different from Control:
*
P < 0.05
**
P < 0.01.
Significantly different from before supplementation (0):
†
P < 0.05.