Table 1.

Ventilation

	Normoxia	Isocapnic hyperpnoea	Isocapnic hypoxia
Arterial O2 saturation (%)	98.8 ± 0.2	99.1 ± 0.2	85.7 ± 0.3*†
Minute ventilation (1 min−1)	8.3 ± 1.2	18.4 ± 2.4*	18.9 ± 2.7*
Breating frequency (breaths min−1)	12.9 ± 1.5	14.0 ± 1.4	14.1 ± 1.5
Tidal volume (ml)	667 ± 63	1444 ± 240*	1474 ± 252*
End-tidal Pco2 (mmHg)	37.6 ± 1.5	38.4 ± 1.1	39.1 ± 1.1

^*P < 0.05 vs. normoxia.

^†P < 0.05 vs. isocapnic hyperpnoea. Values are means ±s.e.m.