Table 2.
Metabolic responses and substrate oxidation during 40 km time-trial. Data are mean (±SE).
| 10 km | 20 km | 30 km | 40 km | ||
|---|---|---|---|---|---|
| HR (bpm) | PLA | 158(2) | 160(3) | 163(4) | 170(3)* |
| CHO | 157(2) | 160(3) | 160(2) | 173(3)* | |
| V̇O2 (l·min-1) | PLA | 3.9 (.1) | 3.9 (.1) | 4.0 (.1) | 4.2 (.1) |
| CHO | 3.9 (.1) | 3.9 (.1) | 4.0 (.2) | 4.4 (.2) | |
| V̇E (l·min-1) | PLA | 89.6 (4.1) | 89.6 (4.4) | 92.8 (3.7) | 104.2 (2.3)† |
| CHO | 93.9 (4.1) | 93.9 (4.1) | 94.9 (5.2) | 113.8 (5.6)* | |
| RER | PLA | .90 (.01) | .87 (.01)‡ | .87 (.01) | .89 (.01) |
| CHO | .92 (.02) | .90 (.01)‡ | .89 (.02)§ | .92 (.02) | |
| Carb. oxidation (g·min-1) | PLA | 3.27 (.23) | 2.77 (.20)‡ | 2.75 (.20) | 3.33 (.29) |
| CHO | 3.68 (.27) | 3.28 (.23) | 3.15 (.33)¶ | 4.06 (.43) | |
| Fat oxidation (g·min-1) | PLA | .64 (.09) | .82 (.05) | .86 (.05) | .76 (.08) |
| CHO | .47 (.12) | .64 (.09) | .73(10) | .57 (.12) |
No differences (p > 0.05) were observed between conditions for overall mean values.
* Significantly different from 10 km, 20 km, and 30 km values
† Significantly different from 20 km and 30 km values
‡ Significantly different from 10 km value
§ Significantly different from 10 km, 20 km, and 40 km values
¶ Significantly different from 40 km value