The Australian Racing Board has seen fit to release a statement regarding hypoxic training in Thoroughbreds. Training in hypoxia is nothing new with the concept being that as altitude increases, the partial pressure of oxygen decreases in proportion to the reduction in the atmosphere pressure and the rate of oxygen transfer from the lungs to the blood cells. This results in proportionately less oxygen being delivered to the tissues of the body. In response to this reduced tissue oxygenation, a variety of physiological adaptations occur including increased circulating red blood cell mass, increased oxygen transport capacity and increased blood buffering capacity resulting in lower lactate levels and higher aerobic thresholds.
That's the theory at least, although at this stage the efficacy of training in hypoxia has not been properly studied under peer-review in Thoroughbreds or Standardbreds as far as we are aware. There is also considerable disagreement in scientific literature in humans to say if the response is significant, if it is better to "live high/train low" or "live low/train high" and its efficacy in sprinting and endurance performance. That said, in South Africa living/training thoroughbreds at higher altitudes but shipping to lower elevations to race is commonplace and there was a very good article written about this in the European Trainer magazine last year which you can read by clicking here.
There are of course some commercially available options for those that can't find themselves training in South Africa. We are also aware of a very well funded facility in Victoria, Australia (hence, we suspect, this release by the ARB) where a high speed treadmill has been placed in a high altitude equine enclosure simulating up to 20,000 feet of elevation and allowing full training of a thoroughbred at altitude. This chamber has only been in existence for a few months now so it is not clear what results, if any, that are coming from that facility, although it is run by a highly respected equine physiologist so we suspect results aren't too far away. All of this of course, should not be confused with the growing presence of hyperbaric chambers which actually increase the pressure of oxygen, in an effort to increase the efficacy of antibiotics, and improve injury repair time.
You can read the whole statement from the ARB here.