View source for Intermittent Hypoxic Exposure

Being exposed to low oxygen for short periods has been shown to provide additional benefits beyond other [[Altitude Training Approaches]]. The technique usually involves [[Breathing]] air with reduced oxygen content for shorter periods. IHE can provide the increase in red blood cell count as longer periods, as well as improving oxygen delivery to the [[Muscle|muscles]]. IHE is normally performed at rest rather than when training, and uses a [[Pulse Oximeter]] to verify the impact of the hypoxia. Also, IHE uses lower oxygen content than other forms of altitude training. For details of the supporting studies for IHE, see [[The Science of Intermittent Hypoxic Exposure]]. It is also possible to exercise while exposed to lower oxygen levels, referred to as [[Intermittent Hypoxic Training]]. 
==Benefits of IHE==
* Improved efficiency in oxygen usage (mitochondrial respiration)
* Increased blood oxygen carrying capacity (not all studies show this)
* Greater resistance to free radicals through improved anti-oxidant defenses
* Adaption in [[Breathing]] patterns at altitude 
* A shift from [[Protein]] to fat as an energy source
* No reduction in training intensity compared with Live High, Train High
* No impaired sleep compared with Live High, Train Low
* Improved lung function for patients with bronchial asthma and chronic obstructive pulmonary disease (COPD).
* Some positive studies of the effect of IHE on Parkinson's Disease, Alzheimer’s Disease, and Cancer using animals.
=Cautions and Contraindications=
Please see [[DIY_Altitude_Training#Cautions|DIY Altitude Training Cautions]].
=Altitude Training Programs=
With an IHE program you can vary how long the hypoxia periods last for, how long the recovery period lasts for, the number of hypoxic bouts, and either the oxygen level or the target [[SpO2|SpO<sub>2</sub>]]. There is no clear direction on the best combination, but here are some general guidelines. 
* Build up your level of hypoxic exposure gradually, over a period of days. 
* Typically the hypoxic period lasts between 3 and 15 minutes. 
* Recovery periods are either equal to the hypoxic periods or shorter.
* Bouts of hypoxia are repeated to give anywhere from 20-90 minutes of total hypoxic time. 
* The target [[SpO2|SpO<sub>2</sub>]] is generally between 85 and 75%. Saturations over 90% do not have any significant impact, and going below 75% is not advised.
* Anecdotal reports indicate that [http://en.wikipedia.org/wiki/Hypoxic_Training_Index Hypoxic Training Index] (HTi) doses of 150 do not produce significant results, where HTi of 200-300 are effective. 
* IHE can be performed daily or for just a few days per week. 
* An IHE program will often build up the duration and [[SpO2|SpO<sub>2</sub>]] over time. 
* During a [[Practical Tapering| Taper]] the IHE is either reduced or stopped.
* Some people find that beginning an IHE routine can make them feel sluggish, as you might expect with a new training stress. 
* There is a wide individual variability in altitude adaptation.
A pattern that is used by a number of studies is IHE for 15 days, with 6 repeats of 5 minutes hypoxic plus 5 minutes recovery (total 30 minutes hypoxia). 
* Days 1 to 5: saturation = 90, 88, 86, 86, 84%. (Using a percentage O2 of 12%.)
* Days 6 to 10: saturation = 82, 82, 80, 80, 78%; (Using a percentage O2 of 11%.)
* Days 11 to 15: saturation = 78, 78, 76, 76, 76%; (Using a percentage O2 of 10% then 9%.)
After this 15 day period there are a number of options depending on your goal:
* For a race, have 3-4 days with no IHE, then the race on the 5th day.
* Use IHE periodically, doing 5-7 days of IHE then 10-15 days without IHE.
* Continue using IHE 3-7 days/week indefinitely. The length of the IHE could be reduced to 15 minutes of hypoxia as either 1x15 minutes or 3x (5 minutes hypoxia plus 5 minutes recovery). 


=AltoLab Programs=
[[AltoLab]] has a series of programs for IHT depending on your schedule and goals. A PDF of the programs are available at [http://www.pharmapacific.com/2013_New_AltoLabSchedules.pdf http://www.pharmapacific.com/2013_New_AltoLabSchedules.pdf]. I've reproduced some of the tables here so that I can calculate the approximate [http://en.wikipedia.org/wiki/Hypoxic_Training_Index Hypoxic Training index] (HTi). The calculation assumes it will take 1 min. to get to the target [[SpO2|SpO<sub>2</sub>]], then the athlete will maintain the average for the rest of the period. These plans give a range of target [[SpO2|SpO<sub>2</sub>]] that is quite narrow, and in my experience it is difficult to achieve that level of control.

==Initiation==
All of the programs start with the following 15 day program:
{| class="wikitable"
! 
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 6x (6H+4R)
| 91
| 89
| 90
| 0
|-
| 6x (6H+4R)
| 91
| 89
| 90
| 0
|-
| 6x (6H+4R)
| 91
| 89
| 90
| 0
|-
| 6x (6H+4R)
| 88
| 86
| 87
| 102
|-
| 6x (6H+4R)
| 88
| 86
| 87
| 102
|-
| 6x (6H+4R)
| 85
| 83
| 84
| 198
|-
| 6x (6H+4R)
| 85
| 83
| 84
| 198
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 6x (6H+4R)
| 80
| 78
| 79
| 366
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|}

==Plan 1 - Standard==
The main plan has the initiation shown above, followed by 15 days' rest, then 5 days IHE. This routine of 15 days' rest and 5 days IHE is then repeated as long as required.
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 6x (6H+4R)
| 85
| 80
| 83
| 246
|-
| 6x (6H+4R)
| 84
| 80
| 82
| 264
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 15 Day Rest
| 
| 
| 
|}

==Plan 2 - Mild==
After the initiation, there is a 7 day rest period, followed by 6 days' IHT/1 day rest that is repeated. The level of hypoxia is much lower. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1 Days Rest
| 
| 
| 
|}

==Plan 3 – Weekly Sports==
This plan has the initiation shown above, followed by 5 days' rest, then 2-3 days' IHE. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 4-5 Days Rest
| 
| 
| 
|}

==Plan 4 – Twice weekly sports==
Plan 4 has two IHE periods per week; 2 IHE, 1 rest, 3 IHE, 1 rest. The level of hypoxia is lower than most other plans. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 1 Day Rest
| 
| 
| 
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 1 Day Rest
| 
| 
| 
|}

==Plan 5 - Extreme==
This plan is intended for more extreme altitude. It follows the initiation with 12 days' rest. After that, the pattern is 6 days IHT followed by 10 days of rest. This plan has the highest level of hypoxic exposure. 
{| class="wikitable"
! Routine
! Max
! Min
! Avg
! HTi
|-
| 6x (6H+4R)
| 80
| 78
| 79
| 366
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 80
| 78
| 79
| 366
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 10 Day Rest
| 
| 
| 
|}

=Plan 1=
The main plan has the initiation shown above, followed by 15 days' rest, then 5 days IHE. This routine of 15 days' rest and 5 days IHE is then repeated as long as required.
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 6x (6H+4R)
| 85
| 80
| 83
| 246
|-
| 6x (6H+4R)
| 84
| 80
| 82
| 264
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 15 Day Rest
| 
| 
| 
|}

==Plan 2==
After the initiation, there is a 7 day rest period, followed by 6 days' IHT/1 day rest that is repeated. The level of hypoxia is much lower. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1x15H
| 90
| 85
| 88
| 36
|-
| 1 Days Rest
| 
| 
| 
|}

==Plan 3==
This plan has the initiation shown above, followed by 5 days' rest, then 2-3 days' IHE. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 82
| 80
| 81
| 300
|-
| 4-5 Days Rest
| 
| 
| 
|}

==Plan 4==
Plan 4 has two IHE periods per week; 2 IHE, 1 rest, 3 IHE, 1 rest. The level of hypoxia is lower than most other plans. 
{| class="wikitable"
! Routine
! Target [[SpO2|SpO<sub>2</sub>]] (Max)
! Target [[SpO2|SpO<sub>2</sub>]] (Min)
! Avg [[SpO2|SpO<sub>2</sub>]]
! HTi
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 1 Day Rest
| 
| 
| 
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 2x (6H+4R)
| 84
| 78
| 81
| 100
|-
| 1 Day Rest
| 
| 
| 
|}

==Plan 5==
This plan is intended for more extreme altitude. It follows the initiation with 12 days' rest. After that, the pattern is 6 days IHT followed by 10 days of rest. This plan has the highest level of hypoxic exposure. 
{| class="wikitable"
! Routine
! Max
! Min
! Avg
! HTi
|-
| 6x (6H+4R)
| 80
| 78
| 79
| 366
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 82
| 79
| 81
| 312
|-
| 6x (6H+4R)
| 80
| 78
| 79
| 366
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 6x (6H+4R)
| 78
| 75
| 77
| 444
|-
| 10 Day Rest
| 
| 
| 
|}

==DIY IHE System==
I have built a [[DIY Altitude Training]] system that is cheap and works well. I typically use it 5-7 days/week, with 5 minutes of hypoxia/2-4 minutes of recovery, repeated for 30-45 minutes. 
==See Also==
* [[The Science of Altitude Training]]
* [[Comparison of Altitude Training Systems]]
* [[Book Review - Altitude Training and Athletic Performance]]
* [[The Science of Intermittent Hypoxic Exposure]] 
* [[AltoLab]]
* [[Viagra, Exercise and Altitude]]
* [[Pulse Oximeter]]
* [[Hypoxic Timer]]