Tissue oxygenation and mitochondrial respiration under different modes of intermittent hypoxia.

We compared the results of five modes of intermittent hypoxia training (IHT) on gastrocnemius muscle Po2 and heart and liver mitochondrial respiration in rats. Minutes of hypoxia, %O2, and recovery minutes on air in each mode were: 1) 5, 12%, 5; 2) 15, 12%, 15; 3) 5, 12%, 15; 4) 5, 7%, 5; and 5) 5, 7%, 15. Mode 1 proved best in that Pmo2 dropped minimally at the end of every hypoxic bout and recovered quickly after each bout.