Table 1.

A comparison of the respiratory responses to daily 20 min exposure to isocapnic (eucapnic) hypoxia with those of isocapnic (eucapnic) normoxia on days 1 and 14

	Isocapnic (eucapnic) normoxia						Isocapnic (eucapnic) hypoxia
	Day 1			Day 14			Day 1			Day 14
	T1	T2	T3	T1	T2	T3	T1	T2	T3	T1	T2	T3
End-tidal PCO2 (mm Hg)
Mean	38.5	39.0	38.4	38.3	38.8	38.5	39.5	39.0	39.3	38.5	38.5	38.6
s.e.m.	0.2	0.4	0.5	0.3	0.3	0.8	0.2	0.3	0.6	0.4	0.5	0.5
End-tidal PO2 (mm Hg)
Mean	94.1	92.6	94.1	96.1	97.0	98.2	91.3	57.0	51.6	94.3	56.7	51.0
s.e.m.	0.6	1.4	0.9	0.7	0.6	1.3	0.5	2.5	2.3	0.8	2.0	0.7
Ventilation (l min−1)
Mean	10.0	10.4	10.8	10.2	9.6	9.2	8.9	10.5	8.8	11.0	14.9*	10.4
s.e.m.	0.4	0.4	0.3	0.4	0.3	0.4	0.5	0.6	0.6	0.7	0.5	0.5

^*Significantly different from hypoxia Day 14, T1 and T3, and normoxia and hypoxia Day 1, T2.

T1, 5min prior to exposure; T2, first 5min of exposure; T3, last 5min of exposure.