Table 1.
Changes in Respiratory and Cardiovascular Measures During Ascent (Mean ± Standard Deviation)
| 1400 m | 3440 m (day 3) | 4240 m (day 7) | p-value (partial-η2) | |
|---|---|---|---|---|
| Weight (kg) | 69.2 ± 12.5 | 69.1 ± 12.1 | 68.3 ± 11.7# | 0.04 (0.4) |
| Minute ventilation (L/minutes) | 8.24 ± 2.09 | 9.48 ± 2.63 | 9.72 ± 2.76 | 0.18 (0.2) |
| Respiration rate (minutes−1) | 11.1 ± 4.0 | 10.6 ± 2.8 | 10.5 ± 2.9 | 0.59 (0.0) |
| Tidal volume (L) | 0.78 ± 0.20 | 0.94 ± 0.34 | 0.96 ± 0.27 | 0.25 (0.2) |
| ET-CO2 (mmHg) | 32 ± 3 | 25 ± 2‡ | 23 ± 3‡ | 0.01 (0.8) |
| SPO2 (%) | 97 ± 1 | 91 ± 4‡ | 88 ± 3‡ | 0.01 (0.8) |
| Hematocrit (%) | 43.9 ± 2.1 | 43.9 ± 3.0 | 45.1 ± 3.5 | 0.58 (0.1) |
| Hemoglobin (g/L) | 132 ± 34 | 142 ± 17 | 143 ± 18 | 0.06 (0.1) |
| AMS scorea | 0 (0–1) | 1.5 (0–2) | 1 (0–2) | 0.02 |
a
Nonparametric analyses presented as median (range), partial-η2 not calculated.
Partial-η2 quantifies effect size and portion of variance accounted for by a specific main/interaction effect ‡altitude effect, p < 0.05 versus 1400 m; #altitude effect, p < 0.05 versus 3440 m.
AMS, acute mountain sickness; ET, end-tidal; SPO2, peripheral arterial oxygen saturation.