***DISCLAIMER***
I don't recommend you trying this. This is for informational purposes, and without consideration of dangers and a safe environment to practice, this can lead to serious injury.
***
I managed to work out a sequence that one can do without any equipment which should simulate the IHT conditions as described in the article, as it did for me while exercising and analyzing with a pulse oximeter. Much less precision towards maintaining a specific SaO2 unless you have an oximeter on hand, but the results due to this inaccuracy are most likely to induce a greater adaptation.
This was created because my father is going to hike to base camp at Everest and he was looking for something to help with acclimatization. The values are tailored for him, having no freediving related adaptations currently, but after the steps I will put the variables I used to reach the IHT equivalent.
1. begin exercise until relaxed, continuing to exercise for the rest of the steps.
2. hyperventilate (quick inhales and exhales; inhaling 3/4 amount of a normal breath; 2 inhales per second).
3. exhale fully.
4. hold your breath.
5. when it begins to feel a little uncomfortable, repeat from step 2, but this time on step 2 only perform 3-6 hyperventilations.
6. continue the cycle for 5 min of exercise.
7. continue exercising normally for 5 min.
8. repeat from step 2.
9. continue full cycle 3 times in total.
Notes (remember these are written to a non-freediver):
Step #2: Every person is different when it comes to hyperventilating. We have different abilities to remove CO2 and this ability improves with practice. So, I think you will probably need to start with 20 hyperventilations on the first cycle and on every cycle after that, 6. The less the better. Also, hyperventilating assists at making your body more suceptible to fainting, therefore you need to closely listen to the sensations of your body for over-doing it. The first cycle requires more hyperventilating than the rest of the cycles to allow you to hold your breath longer on the first hold until your oxygen levels have depleted to a level that you intend to maintain throughout the exercise. (note: for myself I did about 15 hyperventilations for the first instance, and 3-5 for each cycle after that)
If you find you are becomming dizzier with each cycle after holding your breath, then perform less hyperventilation and this will induce a shorter breath hold, if you cycle when the same level of discomfort occurs.
Step #3: Remember we are trying to maintain as little time as possible with oxygen in the lungs, therefore perform these exhalations and inhalations with focus on haste.
Step #4: Holding your breath, especially on exhale is a little disconcerting and awkward. Just relax and don't push anything. There is no success or failure here, so don't worry about a thing. Don't struggle too much and don't give up. Just find the balance. You will probably find you can hold your breath while exercising for only 8-15 seconds. IMPORTANT: It does not really matter how long you hold your breath for, instead all we are interested in, is maintaining a lower level of oxygen in the blood. You will need to experience a subtle discomfort at the end of each breath-hold, but not much more than that. (note: on the pulse oximeter my SaO2 level would drop to low 70s by the end of my breath hold and during the hyperventilations, would rise to high 70s/low 80s. I could have easily adjusted the range higher similar to the IHT)
Step #5 (same as Step #2 but modified): When finishing step #4 DO NOT take a large inhale, or breathe normally, or hold your breath. You must hyperventilate immediately otherwise the CO2 buildup will become intolerable and you will end up becoming replenished with oxygen to normal levels. You now don't hyperventilate as much as the first time, since you are not just trying to satisfy your body's need to stop the build-up of CO2 and maintain the level of O2. By hyperventilating quickly a few times, you can get rid of the nasty CO2 and only replenish a slight amount of O2.
PRECAUTIONS:
1. If you have any history or are unaware of blood pressure troubles, heart conditions, etc... your should consult your doctor regarding your trip and intentions, and therefore the same applies to this type of training. The adaptations can thicken your blood, put stress on your heart, increase blood pressue, etc... all of which under normal circumstances your body has other factors to balance out those adaptations, allowing the body to be healthy and generally even healthier than previously. However, maybe there are conditions where this training would be too sudden or stressful.
2. Easy does it! The steps are the model, but you must be aware that your current body condition may require easing into certain things. Instead of performing this for 5min the first few sessions, maybe only do 2-3min and 6 cycles instead. Maybe hyperventilate a little more at first (say 10 times on each cycle) and if you can perform the full exercise a few sessions, then lessen the amount of hyperventilating to the suggested 5-6 times.
3. Hyperventilating can seriously make you faint, so no sudden movements especially in the vertical direction while performing these exercises. Get to know your body and hyperventilating. Only do 6 times the first time you try hyperventilating and do it laying down or sitting safely in the MIDDLE of your bed. Get to know what it feels like. If safely laying down or sitting in the MIDDLE of your bed, keep increasing how many times you hyperventilate, to find when/if you start getting light headed. Under these same conditions practice some breath holding after hypervenitlating. Just until you are uncomfortable to get a sense of your body. If you determine that you feel light headed after 20 hyperventilations then start with 1/4 of the number of times and slowly increase to see when you start feeling a little light headed. After holding your breath while exercising, and suddenly breathing, you will most likely feel a sudden wave of light-headedness. Note how severe it is and back off on the length of the breath-hold as well as derease the hyperventilating. It should be ok to feel a subtle wave of light-headedness. Just be careful. I felt it every time as I was working this out.
4. This practice is considerably stressful on the body overall. Low-oxygen conditions allow the build up of free-radicals, of which I know little about other than anti-oxidants are essential and vitamins to maintain a healthy body under these types of stresses. Take extra vitamin C and eat lots of vegetables and fruits, preferrably organic. This is of utmost importance. You can become very ill if you allow your body to be stressed in this form without adjusting your diet to the new demands. As well the adaptations often have to do with generating haemoglobin, which requires iron, therefore a good source of iron or iron suppliments is important.
Interesting to note, is that the same effect could not be achieved while remaining motionless. But then we need the exercise and it probably induces more adaptation than at rest. Remaining motionless if I hyperventilated as little as possible to allow me to hold my breath longer, the oxygen requirements would be replenished even if I held my breath to very low levels. Since the metabolism is very low at rest, the returning veinous blood was not depleted significantly, therefore the blood could be replenished quite easily.
Thoughts? Questions? Corrections? Mud-slinging?
Cheers,
Tyler