Table 2.
Whole-body stable isotope calculations
| Time | Group | R | Total fat oxidation (μ mol min−1 kg−1) | Ra,FA (μmol min−1 kg−1) | Rd,FA (μmol min−1 kg−1) | Plasma FA oxidation (μmol min−1 kg−1) | Oxidation of FA non-plasma FA (μmol min−1 kg−1) | FA oxidized (%) |
|---|---|---|---|---|---|---|---|---|
| 30–45 min | FAT | 0.86 ± 0.01* | 25.8 ± 2.4* | 18.1 ± 2.5* | 20.2 ± 2.5* | 13.8 ± 1.2* | 11.3 ± 2.7* | 70 ± 4 |
| CHO | 0.93 ± 0.02 | 13.7 ± 2.9 | 11.3 ± 2.3 | 13.3 ± 2.5 | 8.9 ± 1.2 | 4.8 ± 3.2 | 70 ± 7 | |
| 45–60 min | FAT | 0.86 ± 0.01* | 25.7 ± 3.3* | 20.4 ± 2.1* | 19.3 ± 1.0* | 13.1 ± 1.2* | 12.5 ± 3.8* | 69 ± 6 |
| CHO | 0.93 ± 0.02 | 13.9 ± 2.8 | 12.8 ± 2.1 | 12.5 ± 3.4 | 9.0 ± 0.8 | 4.9 ± 3.3 | 73 ± 7 |
All variables represent data averaged over 30–45 min or 45–60 min of exercise, and values are means ±s.e.m. FA, fatty acid; Ra,FA, whole-body rate of appearance of FA; Rd,FA, whole-body rate of disappearance of FA; R, respiratory exchange ratio. Ra,FA and Rd,FA were calculated according to Steele's non-steady-state equations (see Methods).
*
P < 0.05, FAT vs. CHO.