| Isotime levels | |||||
| 25% | 50% | 75% | 100% | Peak | |
| V′O2 | 11.8 | 9.6 | 7.2 | 7.0 | 8.6 |
| V′CO2 | 12.1 | 10.4 | 7.9 | 7.3 | 9.7 |
| Heart rate beats·min−1 | 4.8 | 5.2 | 4.1 | 4.1 | 5.0 |
| SpO2 | 3.1 | 5.5 | 4.7 | 5.5 | 7.0 |
| RER | 4.4 | 3.6 | 3.0 | 3.0 | 5.2 |
| V′E | 14.4 | 11.7 | 8.2 | 7.3 | 11.3 |
Data are presented as mean within-subject coefficient of variation %. V′O2: oxygen uptake; V′CO2: carbon dioxide output; SpO2: arterial oxygen saturation measured by pulse oximetry; RER: respiratory exchange ratio; V′E: minute ventilation. 25%, 50%, 75%, 100% correspond to exercise time-points corresponding to 25%, 50%, 75% and 100% of the latest exercise time reached in both endurance shuttle walking tests. Peak corresponds to the highest value reache d during the two first endurance shuttle walking tests.