Table 1.
Arterial blood chemistry and cardiovascular responses during the final minute of exercise
| Normoxia |
Normocapnic hypoxia |
Normoxic hypercapnia |
||||
|---|---|---|---|---|---|---|
| Ctrl | Fent | Ctrl | Fent | Ctrl | Fent | |
| SaO2 (%) | 97 ± 0 | 96 ± 2 | 79 ± 2 | 79 ± 1 | 98 ± 1 | 97 ± 2* |
| PaO2 (mmHg) | 84 ± 4 | 81 ± 3* | 43 ± 3 | 44 ± 5 | 105 ± 4 | 104 ± 7 |
| PaCO2 (mmHg) | 32 ± 3 | 33 ± 2* | 33 ± 3 | 33 ± 2 | 50 ± 2 | 50 ± 1 |
| Arterial pH | 7.39 ± 0.03 | 7.37 ± 0.04 | 7.39 ± 0.03 | 7.37 ± 0.04 | 7.26 ± 0.03 | 7.26 ± 0.03 |
| Arterial K+ (mmol·L−1) | 3.9 ± 0.3 | 4.0 ± 0.3 | 3.9 ± 0.2 | 3.9 ± 0.2 | 4.0 ± 0.4 | 3.8 ± 0.4 |
| Arterial lactate (mmol·L−1) | 3.0 ± 1.2 | 3.3 ± 1.1 | 3.0 ± 1.0 | 3.3 ± 0.8 | 2.4 ± 0.6 | 2.8 ± 0.9 |
| MAP (mmHg) | 108 ± 7 | 99 ± 11* | 113 ± 8 | 98 ± 11* | 115 ± 7 | 105 ± 9*’ |
| SYS (mmHg) | 152 ± 14 | 139 ± 18* | 162 ± 17 | 137 ± 15* | 164 ± 16 | 149 ± 17*’ |
| DIA (mmHg) | 86 ± 5 | 80 ± 9* | 87 ± 6 | 78 ± 9* | 90 ± 4 | 82 ± 6* |
| HR (beats·min−1) | 109 ± 20 | 107 ± 21 | 130 ± 20 | 121 ± 24*’ | 123 ± 18 | 114 ± 15* |
| LBF (L·min−1) | 3.0 ± 0.7 | 2.6 ± 0.7* | 3.0 ± 0.6 | 2.8 ± 0.9 | 3.1 ± 0.7 | 2.8 ± 0.9* |
| LVC (mL·min−1·mmHg−1) | 27.6 ± 7.0 | 25.9 ± 7.2 | 26.5 ± 5.3 | 28.3 ± 7.0 | 27.0 ± 6.2 | 27.1 ± 9.1 |
Exercise was performed at 60% of peak work rate (33 ± 9 W; = 11). Ctrl: exercise performed with intact leg muscle afferent feedback; Fent: exercise performed with attenuated leg muscle afferent feedback; SaO2: arterial haemoglobin saturation; PaO2: arterial partial pressure of O2; PaCO2: arterial partial pressure of CO2; MAP: mean arterial pressure; SYS: systolic blood pressure; DIA: diastolic blood pressure; HR: heart rate; LBF: leg blood flow; LVC: leg vascular conductance
*
< 0.05 . Ctrl; < 0.05 .normoxia. Data were analysed using two-way repeated-measure ANOVA with Tukey’s test and are presented as mean ± SD.