Intermittent hypoxic training

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Intermittent hypoxic training (IHT), also known as intermittent hypoxic therapy, is a technique aimed at improving human performance by way of adaptation to reduced oxygen.

Contents

An IHT session consists of an interval of several minutes breathing hypoxic (low oxygen) air, alternated with intervals breathing ambient (normoxic) or hyperoxic air. The procedure may be repeated several times in variable-length sessions per day, depending on a physician's prescription or a manufacturer's protocol. [1] Standard practice is for the patient to remain stationary while breathing hypoxic air via a hand-held mask. The therapy is delivered using a hypoxicator during the day time, allowing the dosage to be monitored. Biofeedback can be delivered using a pulse oximeter.

Effects

A number of effects are reported. [2] [3] [ clarification needed ] It is important to differentiate between physiological adaptations to mild hypoxia and re-oxygenation episodes (i.e., the IHT protocol) and frequent nocturnal suffocation awakenings produced by sleep apnea, which might result in various pathologies. [4] [ clarification needed ]

Applications

IHT has been used to try to improve performance in sports. [5] and has been used in a number of health conditions. [6] [ clarification needed ]

See also

Related Research Articles

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Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body. Although hypoxia is often a pathological condition, variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise.

<span class="mw-page-title-main">Tumor hypoxia</span> Situation where tumor cells have been deprived of oxygen

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<span class="mw-page-title-main">Polycythemia</span> Laboratory diagnosis of high hemoglobin content in blood

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<span class="mw-page-title-main">Generalized hypoxia</span> Medical condition of oxygen deprivation

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<span class="mw-page-title-main">Altitude training</span> Athletic training at high elevations

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A hypoxicator is a medical device intended to provide a stimulus for the adaptation of an individual's cardiovascular system by means of breathing reduced oxygen hypoxic air and triggering mechanisms of compensation. The aim of intermittent hypoxic training or hypoxic therapy conducted with such a device is to obtain benefits in physical performance and wellbeing through improved oxygen metabolism.

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The Hypoxic Training index (HTi) provides an objective measure of the hypoxic stress delivered during the Intermittent Hypoxic Training (IHT) session, compared to simple recording the inhaled fraction of oxygen (FiO2). HTi provides a figure (index) of dosage received by the individual at the end of the session. Knowledge of HTi can therefore be used to alter the training regime for different individuals, compensating for individual variability, and can be used in scientific studies to ensure that subject exposure was correctly controlled.

<span class="mw-page-title-main">Organisms at high altitude</span> Organisms capable of living at high altitudes

Organisms can live at high altitude, either on land, in water, or while flying. Decreased oxygen availability and decreased temperature make life at such altitudes challenging, though many species have been successfully adapted via considerable physiological changes. As opposed to short-term acclimatisation, high-altitude adaptation means irreversible, evolved physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. Among vertebrates, only few mammals and certain birds are known to have completely adapted to high-altitude environments.

Fish are exposed to large oxygen fluctuations in their aquatic environment since the inherent properties of water can result in marked spatial and temporal differences in the concentration of oxygen. Fish respond to hypoxia with varied behavioral, physiological, and cellular responses to maintain homeostasis and organism function in an oxygen-depleted environment. The biggest challenge fish face when exposed to low oxygen conditions is maintaining metabolic energy balance, as 95% of the oxygen consumed by fish is used for ATP production releasing the chemical energy of nutrients through the mitochondrial electron transport chain. Therefore, hypoxia survival requires a coordinated response to secure more oxygen from the depleted environment and counteract the metabolic consequences of decreased ATP production at the mitochondria.

High-altitude adaptation in humans is an instance of evolutionary modification in certain human populations, including those of Tibet in Asia, the Andes of the Americas, and Ethiopia in Africa, who have acquired the ability to survive at altitudes above 2,500 meters. This adaptation means irreversible, long-term physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. While the rest of the human population would suffer serious health consequences, the indigenous inhabitants of these regions thrive well in the highest parts of the world. These humans have undergone extensive physiological and genetic changes, particularly in the regulatory systems of oxygen respiration and blood circulation, when compared to the general lowland population.

<span class="mw-page-title-main">Intermittent hypoxia</span>

Intermittent hypoxia (also known as episodic hypoxia) is an intervention in which a person or animal undergoes alternating periods of normoxia and hypoxia. Normoxia is defined as exposure to oxygen levels normally found in Earth's atmosphere (~21% O2) and hypoxia as any oxygen levels lower than those of normoxia. Normally, exposure to hypoxia is negatively associated to physiological changes to the body, such as altitude sickness. However, when used in moderation, intermittent hypoxia may be used clinically as a means to alleviate various pathological conditions.

References

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  2. Manukhina EB, Downey HF, Mallet RT (April 2006). "Formation and Role of Nitric Oxide Stores in Adaptation to Hypoxia". Oxygen Transport to Tissue XXVII. Advances in Experimental Medicine and Biology. Vol. 231. pp.  343–65. doi:10.1007/0-387-29540-2_6. ISBN   978-0-387-29543-5. PMID   16565431.{{cite book}}: |journal= ignored (help)
  3. Gore CJ, Clark SA, Saunders PU (September 2007). "Nonhematological mechanisms of improved sea-level performance after hypoxic exposure". Medicine and Science in Sports and Exercise. 39 (9): 1600–9. doi: 10.1249/mss.0b013e3180de49d3 . PMID   17805094.
  4. Serebrovskaya TV, Manukhina EB, Smith ML, Downey HF, Mallet RT (June 2008). "Intermittent hypoxia: cause of or therapy for systemic hypertension?". Experimental Biology and Medicine. 233 (6): 627–50. doi:10.3181/0710-MR-267. PMID   18408145. S2CID   20045656.
  5. Levine, BD (2002). "Intermittent hypoxic training: fact and fancy". High Altitude Medicine & Biology. 3 (2): 177–93. doi:10.1089/15270290260131911. PMID   12162862.
  6. Serebrovskaya TV (2002). "Intermittent hypoxia research in the former soviet union and the commonwealth of independent States: history and review of the concept and selected applications". High Altitude Medicine & Biology. 3 (2): 205–21. doi:10.1089/15270290260131939. PMID   12162864. S2CID   28834625.