Table 1. Swimming time in test on exercise tolerance. Data are means (± SEM).

Groups	Control	CE (4 wk)	IHT (2 wk)	CE+IHT during the first two weeks	CE+IHT during the last two weeks
Endurance (min)	10.0 (2.0)	18.6 (1.7)*	32.4 (2.1)*, †	68.2 (1.5)*, †	63.9 (1.4)*, †

Abbreviations: CE= chronic exercise, HT= intermittent hypoxic training, CE+IHT= chronic exercise in combination with sessions of intermittent hypoxic training during the first or the last two weeks.* p < 0.05 compared with control group,†  p < 0.05 between experimental groups.