Table 1.

SpO2, HR and RespR recorded at SL, 3000 m and 4000 m

	SL	3000 m	4000 m
SpO2 (%)	97 ± 1	90 ± 3	84 ± 4 §
HR (1/min)	72 ± 5	77 ± 5	84 ± 5 ‡
RespR (1/min)	22 ± 2	23 ± 2	24 ± 2 †

§ Significantly lower compared with the value at SL and 3000 m (both P < 0.001).

‡ Significantly increase compared with the value at SL (P < 0.001) and 3000 m (P = 0.002).

† Significantly change compared to the value at SL (P = 0.012), but there was no significant change between SL and 3000 m (P = 0.169), neither between 3000 m and 4000 m (P = 0.217).