Altitude training, IHT, Hypercapnia recovery and the benefits.

Many athletes now days have some sort of altitude camp or Intermittent Hypoxic Training (IHT). There are various combinations of Living high training high or living high training low etc. With living high and training low (which could be done using a altitude tent) a athlete can avoid reduced muscle recruitment found when training high so have a better training session at lower altitude with the benefit of increased red blood cells.  A more common practice now days is IHT which has shown to be more effective than altitude tents. Depending on the protocol the body will adapt to the hypoxia effect and increase red blood cell production so there is more oxygen carrying blood going to the working muscles.

If you have read the post FaCT way of looking at the body you might understand why there could be altitude responders and non-responders. Example: If your muscles are the limitation before the altitude camp, then after e.g. three weeks at altitude  they may not have changed at all but in fact the muscle "may" be worse from the camp due to a reduced muscle recruitment at altitude. If that is so and we have better oxygen transportation with more Oxygenated blood (higher red blood cell count) it is much easier for the heart to keep the vital organs happy. Pumping more blood to the muscle will make no sense, as the limitation of muscle can't take more oxygen in anyway (muscle recruitment/utilization). This would be a non-responder and the same holds true when athletes use EPO and in some cases there are also non-responders. So once again knowing what each individual athletes limitation is through testing and not guessing will help one to understand the effects of training at altitude.

What I would like to give more in depth information on is the lesser known benefits of Hypoxia or Hypercapnia.  Many of the ideas come from the Russian school and one of the "leading" researchers is, Dr. Buteyko. Here is a abstract which might make you see the bigger picture.

• Oxygenation: Carbon dioxide (CO2) plays a large role in oxygen transport from the blood to the cells of the brain and body. A reduction in CO2 levels brings with it reduced oxygenation of tissue and vital organs (Verigo-Bohr Effect).
• Acid/Alkaline Balance and the Immune System: CO2, through its conversion to carbonic acid, is a primary regulator of the acid/alkaline balance of the body. 
• Vessels: CO2 helps to dilate smooth muscle tissue.
• The Cardiovascular System: CO2 helps regulate the cardiovascular system.
• The Digestive System: A direct relationship exists between the level of CO2 in the body and the functioning of the digestive glands.

Tatiana V. Serbrovskaya (High Altitude Medicine & Biology ( Department of hypoxic States, Bogomoletz Institute of physiology (Kiev Ukraine ) Volume 3, number 2 2002 @ Mary Ann Liebert Inc.

"Intermittent hypoxia research in the former Soviet Union and the Commonwealth of Independent States : History and review of the concept and selected applications. High Alt Med Biol 3:205-221,2002.- This review aims to summarize the basic research in the field of intermittent hypoxia in the Soviet Union and the Commonwealth of Independent States (cis) that scientists in other Western countries may not be familiar with, since Soviet scientists were essentially cut off from the global scientific community for about 60 years. In the 1930s the concept of repeated hypoxic training was developed and the following induction methods were utilized: repeat stays at high-mountain camps for several weeks, regular high altitude flights by plane, training in altitude chambers, and training by inhalation of low-oxygen-gas mixture. To the present day, intermittent hypoxic training (IHT) has been used extensively for altitude pre acclimatization; for the treatment of a variety of clinical disorders, including chronic lung diseases, bronchial asthma, hypertension, diabetes mellitus, Parkinson's disease, emotional disorders, and radiation toxicity, in prophylaxis of certain occupational diseases; and in sports. The basic mechanisms underlying the beneficial effects of IHT are mainly in three areas: regulation of respiration, free-radical production, and mitochondrial respiration. It was found that IHT induces increased ventilatory sensitivity to hypoxia, as well as other hypoxia-related physiological changes, such as increased hematopoiesis, alveolar ventilation and lung diffusion capacity, and alterations in the autonomic nervous system. Due to IHT, antioxidant defence mechanisms are stimulated, cellular membranes become more stable, Ca2+ elimination from the cytoplasm is increased, and O2 transport in tissue is improved. IHT induces changes within mitochondria , involving NAD-dependent metabolism, that increase the efficiency of oxygen utilization in ATP production. These effects are mediated partly by NO-dependent reactions. The marked individual variability both in animals and humans in the response to, and tolerance of, hypoxia is described. Studies from Soviet Union and the CIS significantly contributed to the understanding of intermittent hypoxia and its possible beneficial effects and should stimulate further research in this direction in other countries."

If you are still awake and have followed up to now well done!  So from these benefits one can summarise that IHT has many health benefits also.  Athletes are known to use Hypercapnia for recovery from day after day hard sessions or stage races but the protocol for this is hard to find and one would unlikely complete a full IHT course.  It is a matter of research and thinking how  and when to best apply it after ie a hard race.    

Here is another article to read. The lung and carbon dioxide:

There are many manufacturers of equipment that can be used for IHT and hypercapnia ie  AltiPower, the main disadvantage is maintenance cost of the CO2 filters, but also it can be hard to control SpO2 levels, the SpiroTiger  can be "abused" and allot more precisely control SpO2 levels through breathing alone. Disclaimer: SpiroTiger is NOT build to be used as IHT equipment but only as a diaphragmatic endurance training equipment. It is essential that with any IHT equipment a pCO2 and at the minimum a  Pulse Oximeter is used during IHT.  Dropping the blood saturation (SpO2)  to low, could lead to hospitalization or even death.