On a cellular level the benefits are similar to IHT.

The added advantage of a hypoxic workout is in the targeting of specific muscle groups, stimulating them to become more efficient.

Normal sea-level training will only drop Arterial Oxygen Saturation (SaO2) a couple of % from its usual 96-98%. A Hypoxic workout at a moderate intensity will drop this measure of oxygen saturation in the blood to the 80% or 70%. This de saturation replicates what happens at high altitude.

This deep hypoxia in the muscles stimulates a whole host of adaptations that make them more efficient.

One interesting adaptation is in the mitochondria. Mitochondria are the energy plants located within every cell of the body; they use glucose and oxygen to produce ATP, our main energy source.

Deep hypoxia stimulates the enzymes responsible for producing more efficient Mitochondria and increasing its density. This phenomenon does not occur in sea-level exercising alone.

Another advantage of a hypoxic workout is the amount of calories burnt. No other modality burns as many calories in as short a space of time. This is ideal for weight loss.