Fig. 7.

Average values of minute ventilation recorded before, during, and following exposure to intermittent hypoxia on the initial and final days of the protocol. Average values for minute ventilation recorded from the last 5 min of baseline, the last 2 min of each episode of hypoxia (indicated by vertical tick mark on x-axis), the last 2 min of each normoxic period that separated the hypoxic episodes, and the 30-min poststimuli recovery period which is divided into six 5-min segments. The data were collected during and following administration of the intermittent hypoxia protocol on the initial days of the protocol in the morning (days 2 and 3: ○) and evening (day 1: □) and on the final days of the protocol in the morning (days 8 and 9: ●) and in the evening (day 10: ■). Notice that minute ventilation during each trial was significantly greater during end recovery compared with baseline. In addition, note that minute ventilation during end recovery was greater in the evening compared with the morning on the initial and final days of the protocol. Also note that minute ventilation was greater on the final days compared with the initial days of the protocol during the morning studies. *Significantly different from baseline. ‡Significantly different from AM initial day. §Significantly different from AM initial day and AM final day.